As I have never been to NYC and I live on the West Coast (it's not exactly cheap to fly out to NYC, ya know), I haven't seen shows on Broadway, but I've seen copious amounts of touring and regional shows....(let's just say I'm a bit of a drama geek)
Touring Shows:
Mamma Mia(x2, current touring cast isn't all that great, but it's still pure fluffy fun entertainment)
Phantom of the Opera (was my 2nd huge musical obsession as a kid...I almost cried when I got the tickets, and that was when I was like 8 or 9)
Rent (I'm a huge RentHead...it's almost pathetic how much I love this show)
Cats
Fosse (x2)
Porgy and Bess (I don't know how I got dragged to go to this show...it was painful)
Producers (well, haven't seen it yet, but I've got my tickets for when the tour hits the hometown in June)
We've got this thing here in Sacramento (where I live) called the Music Circus and it's put on by California Musical Theatre, and they do some pretty great professional shows...it's pretty well-known in NYC and the such. I've seen Cats, Into the Woods, Joseph and the Amazing Technicolor Dreamcoat, Wizard of Oz, and so much more that they've done, and their shows have been better than a lot of tours I've seen. I also saw a stellar production of the off-Broadway "Bat Boy" done by a local high school. It was awe-frickin-some. But I may be a bit biased, seeing as I auditioned for it and most of my friends were in it...
I'm hitting NYC this summer, though, after over 2 years of begging and complaining to the parentals. We're gonna see Wicked (I've been a fan of this show since its San Francisco tryout run last summer), Rent (I can't go to NYC and not see Rent again, it's against my credo), probably some Disney on Broadway show (for the whole family...I can't exactly take my little 10 year old brother to Rent), and hopefully Avenue Q. I am in lurve with Avenue Q...so funny. But there's so much more I'd like to see...especially Cabaret, but since that's closed I don't think I'll be seeing that anytime soon.