Robin Tunney (Ep. 1.1, “Pilot”)
Character: a kindergarten teacher who becomes dysphasic and starts having seizures. Turns out she’s invested with tapeworms.

Sam Trammell (Ep. 1.4, “Maternity”)
Character: the father of a baby girl that’s not even out of the maternity ward and already on death’s door from a virus.

Elizabeth Mitchell (Ep. 1.5, “Damned If you Don’t”)
Character: a nun who looks like she’s suffering from stigmata but is later discovered to be suffering an allergic reaction to a copper cross IUD left over from her, uh, wilder days.

Dominic Purcell (Ep. 1.6, “Fidelity”)
Character: a husband whose wife – the Patient of the Week – turns out to have been unfaithful.

Amanda Seyfried (Ep. 1.11, “Detox”)
Character: girlfriend to the Patient of the Week.

Scott Foley (Ep. 1.12, “Sports Medicine”)
Character: a baseball player suffering cadmium poisoning from all the pot he’s been smoking.

Joe Morton (Ep. 1.17, “Role Model”)
Character: a senator suffering the after-effects of an epilepsy treatment from childhood

John Cho (Ep. 1.20, “Love Hurts”)
Character: a guy who, after spilling apple juice on House’s clothes, ends up being diagnosed by him as having had a stroke. Upon further investigation, it’s determined that he has a trauma-induced aneurysm as a result of a preference for sadomasochism.

Carmen Electra (Ep. 1.21, “Three Stories”)
Character: While begrudgingly lecturing a classroom of medical students about a past patient who is depicted as looking like Carmen Electra playing miniature golf. In reality, the patient was actually a male golfer…and he played regular golf, by the way. (Who knew miniature golf could be so sexy?)

LL Cool J (Ep.2.1, “Acceptance”)
Character: a death-row inmate suffering from pheochromocytoma.

Ron Livingston (Ep. 2.4, “TB or Not TB”)
Character: a famous doctor who thinks he has tuberculosis. He doesn’t. It’s actually a tumor and a pancreas problem.

Taraji P. Henson (Ep. 2.6, “Spin”)
Character: the publicist for a famous bicyclist.

Cynthia Nixon (Ep. 2.9, “Deception”)
Character: an anemic woman who turns out to suffer from Münchausen’s syndrome.

Elle Fanning (Ep. 2.11, “Need to Know”)
Character: a little girl whose mom is swiping her Ritalin.

Howard Hesseman (Ep. 2.14, “Sex Kills”)
Character: a man who, in addition to suffering from a brain infection, is also sleeping with his ex-wife, who’s estranged from their daughter. It’s a family affair!

Michelle Trachtenberg (Ep. 2.16, “Safe”)
Character: a teenage girl who, in addition to having survived a car accident only by having a heart transplant, ends up suffering from an acute case of Tick in the Vagina. I only wish I was joking.

Jayma Mays (Ep. 2.18, “Sleeping Dogs Lie”)
Character: a poor, sweet girl who’s contracted bubonic plague through the fleas of her dog.

Thomas Dekker (Ep. 2.19, “House vs. God”)
Character: a faith healer who, rather embarrassingly, turns out to be suffering from a nasty case of herpes.

William Katt (Ep. 2.19, “House vs. God”)
Character: the father of the aforementioned faith healer.

D.B. Sweeney (Ep. 2.23, “Who’s Your Daddy?”)
Character: an old buddy of House’s who finds himself in the midst of a Katrina-related paternity situation.

Elias Koteas (Ep. 2.24, “No Reason”)
Character: a former patient of House’s who’s so disgruntled that he storms into the hospital and promptly shoots House twice. Which, really, isn’t all that surprising.

Kathleen Quinlan (Ep. 3.1, “Meaning”)
Character: the wife of a brain cancer surgery patient who’s paralyzed and in a wheelchair.

Sheryl Lee (Ep. 3.2, “Cane and Able”)
Character: the mother of a seven-year-old boy suffering from rectal bleeding and claims of being tortured by aliens.

Joel Grey (Ep. 3.3, “Informed Consent”)
Character: a noted cancer doctor who, as a result of suffering from the disease himself, begs House for euthanasia.

John Larroquette (Ep. 3.7, “Son of Coma Guy”)
Character: a gentleman in a vegetative state who, thanks to a cocktail of L-Dopa and amphetamines, is awakened long enough to reconnect with his son.

Patrick Fugit (Ep. 3.8, “Whac-A-Mole”)
Character: an 18-year-old who has a heart attack because, as it turns out, he needs a bone marrow transplant.

Meagan Good (Ep. 3.11, “Words and Deeds”)
Character: a firefighter who stands beside one of her medically-challenged coworkers

Dave Matthews (Ep. 3.15, “Half-Wit”)
Character: a pianist deals with a neurological condition which may impair his ability to play.

Kurtwood Smith (Ep. 3.15, “Half-Wit”)
Character: the father of the aforementioned pianist.

Marc Blucas (Ep. 3.16, “Top Secret”)
Character: a veteran who claims to have a nasty case of Gulf War Syndrome but is actually stuck with hereditary hemorrhagic telangiectasia instead.

Bailee Madison (Ep. 3.19, “Act Your Age”)
Character: a six-year-old who’s been affected by their father’s sexual-enhancement cream and, as a result, is going through puberty early.

Lyndsy Fonseca (Ep. 3.22, “Resignation”)
Character: a 19-year-old martial artist drinks drain cleaner and then pretends she hasn’t.

Piper Perabo (Ep. 3.22, “Resignation”)
Character: a vegan and nutritionist who thinks House is interested in her for a job and then gets upset when she realizes it’s more about her, uh, other assets.

Frank Whaley (Ep. 4.5, “Mirror, Mirror”)
Character: a mystery man who comes into the hospital and claims to have numerous symptoms while also suffering from some real ones.

Jeremy Renner (Ep. 4.9, “Games”)
Character: a grunge rocker whose addition to heroin is the least of his problems.

Mira Sorvino (Ep. 4.11, “Frozen”)
Character: a researcher in Antarctica who has to be diagnosed by House via webcam.

Felicia Day (Ep. 5.2, “Not Cancer”)
Character: a teacher who had a corneal transplant and is now dealing with a major brain problem.

Breckin Meyer (Ep. 5.3, “Adverse Events”)
Character: an artist who suffers from a gastrointestinal mass after taking an experimental antacid.

Sherilyn Fenn (Ep. 5.11, “Joy to the World”)
Character: the mother of a teenage girl suffering from both pregnancy and terminal cancer.

Judy Greer (Ep. 5.18, “Here Kitty”)
Character: a woman convinced that she’s going to die because a cat with a disconcerting tendency to sleep next to people on the last night of their lives slept next to her.

Mos Def (Ep. 5.19, “Locked In”)
Character: a guy who gets into a bicycle accident and gets locked-in syndrome for this trouble, meaning that he can think and is fully aware but can’t move or tell anyone of his awareness.

Meat Loaf (Ep. 5.20, “Simple Explanation”)
Character: a terminal patient who, like his life’s not bad enough already, has to endure watching his wife start to succumb to a resperatory ailment.

Carl Reiner (Ep. 5.24, “Both Sides Now”)
Character: an elderly man who claims to have a “squawking ” problem – his term for acid reflux, apparently – but actually has pancreatic cancer.

Curtis Armstrong (Ep. 6.1, “Broken”)
Character: One of House’s fellow patients at Mayfield Psychiatric Hospital.

James Earl Jones (Ep. 6.3, “The Tyrant”)
Character: a dying African dictator who nobody wants to save because he’s pro-ethnic-cleansing. Can you blame them, though? I mean, really…

Joshua Malina (Ep. 6.9, “Wilson”)
Character: a former patient of Wilson’s who asks him for part of his liver and, after getting it, proceeds to prove himself to be as much of a user as House is.

Ethan Embry (Ep. 6.10, “The Down Low”)
Character: a drug dealer suffering from the repeated aneurysms brought on by Hughes-Stovin Syndrome.

Orlando Jones (Ep. 6.12, “Moving the Chains”)
Character: Foreman’s brother. They’re not real close.

Laura Prepon (Ep. 6.14, “Private Lives”)
Character: A workaholic blogger with a case of Whipple’s Disease. It’s a gastrointestinal disorder. Any more detail would just freak us both out.

Sarah Wayne Callies (Ep. 6.18, “Open and Shut”)
Character: a woman whose open marriage makes it decidedly difficult to determine her ailment.

Jennifer Grey (Ep. 7.5, “Unplanned Parenthood”)
Character: a woman who gives birth to a baby with breathing problems, only to find out that she has melanoma and has passed it on to her child.

Amy Irving (Ep. 7.3, “Unwritten”)
Character: the author of a popular series of children’s books who has a seizure in the middle of trying to commit suicide.

Jack Coleman (Ep. 7.6, “Office Politics”)
Character: a senator’s campaign manager who has kidney failure. Oh, also, he probably had sex with the senator.

Matthew Lillard (Ep. 7.9, “Larger Than Life”)
Character: a musician who learns that parents aren’t fucking around when they tell you that chicken pox can be a major hassle when contracted by adults.

Donal Logue (Ep. 7.20, “Changes”)
Character: a lottery winner whose paralysis and cancer may or may not be the result of his new millionaire lifestyle.

David Costabile (Ep. 7.20, “Changes”)
Character: the lottery winner’s shady cousin.

Michael Pare (Ep. 8.1, “Twenty Vicodin”)
Character: The warden of the prison House gets thrown in after driving his car into Cuddy’s house.

Wentworth Miller (Ep. 8.3, “Charity Case”)
Character: a philanthropist who, in the midst of his own medical issues, offers to donate a kidney to a patient.

Michael Nouri (Ep. 8.4, “Risky Business”)
Character: a businessman whose constant trips to China may be the cause of his medical woes.

Billy Connolly (Ep. 8.14, “Love is Blind”)
Character: the man who would be House’s next stepfather. (In other words, the guy’s sleeping with House’s mom.)

Peter Weller (Ep. 8.20, “Post Mortem”)
Character: another physician at the hospital, one who looks suspiciously like the man who directed this episode.

James LeGros (Ep. 8.22, “Everybody Dies”)
Character: a drug addict who causes House to reflect on his life.

Chi McBride (Season 1)
Character: a billionaire pharmaceutical company owner who donates US$100 million to the hospital in return for becoming chairman of the board. He doesn’t like House. At all. Which is why he leaves quickly.

Sela Ward (Seasons 1 & 2)
Character: House’s ex-girlfriend, who turns up because she wants him to treat her husband, who’s suffering from acute intermittent porphyria. House thinks he’s going to get back together with his ex. He’s wrong.

Charles S. Dutton (Seasons 2 & 3)
Character: Foreman’s rather religious father.

R. Lee Ermey (Seasons 2 & 5)
Character: House’s father. Except it later turns out that he wasn’t actually House’s father after all. But that doesn’t stop him from grieving when he dies.

Diane Baker ( Seasons 2, 5 & 8 )
Character: House’s mother. Things get weird when she finds someone new in the wake of her husband’s death.

David Morse (Season 3)
Character: a clinic patient of House’s who gets pissed off at the way House treats him, and because he’s a detective, he proceeds to make House’s life a living hell for several episodes.

Leighton Meester (Season 3)
Character: House’s stalker. Actually, she only stalked him for two episodes, but it still technically counts.

Kadeem Hardison (Season 3)
Character: House’s attorney while he’s being taunted by David Morse’s character

Fred Durst (Season 4)
Character: the bartender who took House’s keys and forced him to ride the bus home, which subsequently wrecked and killed Amber (Anne Dudek), Wilson’s girlfriend.

Lori Petty (Season 5)
Character: a patient involved in the Huntington’s disease drug trials with Thirteen.

Andre Braugher (Season 6)
Character: House’s therapist when he’s doin’ time at the Mayfield Psychiatric Hospital. The two end up bonding somewhat after House’s release.

Cynthia Watros (Seasons 6 & 7)
Character: Wilson’s first wife. They start dating again. It doesn’t work out. Again.

Candice Bergen (Season 7)
Character: Cuddy’s mother

Paula Marshall (Season 7)
Character: Cuddy’s sister.