Serendipity- check amazon or ebay’s auctions for a copy of Roz & Guil. That’s how I got mine, and it was only about $25, IIRC.
AWB- I saw King Lear and Midsummer at the Shakespeare Theatre. Aren’t they exquisite?
My favorites include:
King Lear
Midsummer (it was the first play I was in… call me sentimental.)
Macbeth
Roz & Guil are dead
Candide
Six Degrees of Separation
Stones (It’s the first play I wrote. Allow me my arrogance.)
Also, Another American: Asking and Telling.
I’m seeing Roz and Guil tonight at NYU, by the way. I’ll let you all know how it is.
MR
Please, I’d be very interested if you can can come up with that and any online reviews.
R&G Are Dead is a favorite of mine, and Equus, & Hank4&5, but to go beyond me-tooism, “Wit” by Margaret Edson is way too good to be a first play by a college senior 
I have a soft spot for the silly festival comedies, expecially Twelfth Night and Much Ado About Nothing. One of the best dramas I’ve seen produced was 'Night Mother. It was horrifically difficult to watch, but amazing to see it done right.
Occasionally I go for outright cheese though. My roommate bought us tickets to go see Mamma Mia, the musical entirely based on old ABBA tunes, for next weekend. I’ll be sure to file a full report.
Measure for Measure, The Tempest, Hamlet by Shakespeare
Aria di Capo by Edna St. Vincent Millay
Equus by Peter Shaffer
Emma’s Child by Kristine Thatcher
Who’s Afraid of Virginia Woolf? by Edward Albee
Cinderella Waltz by Don Nigro
There are a lot more that I like/love, but they’re all at home and I haven’t read them in a while. The Royal Shakespeare Company did a wonderful version of Measure for Measure a couple of years ago, and I’ve been smitten ever since. And I’ve never seen a production of Equus; I hope some Seattle theatre decides to do it soon!
Ken Conner. Lives in New Orleans, according to the theatre people.
Unfortunately, the reviews are in the archived sections on-line and there is a charge to read them.
“Wit” just finished a very successful run with Orlando Theatre Project (ironically, based now in Seminole County), though not without controversy over the nudity. That was resolved before the production began, and it was refreshing to see the support that local theatre got from the population in general (feeling that the controversy was unfounded).
I second the nomination of “Sleuth” by Anthony Shaeffer. Not only a great play that keeps you guessing until the very, very end, but also what a workout for the actors! I played Andrew, and the play makes you work really hard. You have to utterly dominate Milo in the first act, then lose it with just as much energy in the second act!
Anthony Shaeffer also wrote “Whodunit?”, which hasn’t been turned into a movie. It has one of the best closing lines in any stage mystery.
Hamlet is pretty cool. I had to read it for class, and it kicks!
As for musicals, I’d go with Jekyll and Hyde.
I just thought of a musical that I love that I haven’t yet seen mentioned: A Funny Thing Happened On the Way to the Forum.
andygirl: Thanks for the tip! I’ll have to direct my mom over there for some Christmas shopping.
My favorites of a short list of plays I’ve seen.
a) Les Miserables Only play I’ve ever cried at, just hits you there…I also loved the book.
b) A Funny Thing Happened on the Way to the Forum The star was from Dayton, modified the play to suit the crowd.
c) Fiddler on the Roof Theo Bikal was Tevye, this was about five years ago. Part of the fun with this one was my cousin was in it playing the knife monger. Got to hear all the fun stuff that was going on behind the scenes.