I've been very lucky. Never met anyone who wasn't super sweet or at least gracious with me. I'm usually hesitant to approach famous people because if they turn out to be jerks, it's so disappointing. I know a few people who've met
Henry Rollins (Black Flag, then all that spoken word stuff) who were treated like garbage by him. Same thing goes for
Michael Stipe of R.E.M.
My favorites -
Pete Townshend (The Who). He's my lyrical hero, and The Who is my all-time favorite band, so meeting him was HUGE for me. I was shaking from head to toe! A friend told Pete, "She's really shy." -- which is true, in general, but at that time, I was more nervous than anything, and I said so. Pete looked at me and said "There's a big difference between shyness and nervousness." Honestly, he could've said
"Some people like licorice", or
"Blue wall clock overture" for all I cared -- all that mattered was he was
talking to ME! I happened to still have the ticket stub from the Who show I'd seen at Madison Square Garden a few weeks before in my wallet, and he signed it for me. This was in 1995 or so, and it's been in a frame ever since
Adam Graves from the New York Rangers!

OMG, I was totally in love with him. And I was lucky enough to be working at a charity event he attended. I risked reprimand by going outside to meet him, but there was no way I was letting him leave without meeting him. My favorite hockey player ever! I stood in the rain waiting for him to come out, and had to be prodded by a co-worker when he came out. Adam, noticing my rain-drenched state, said something like, "Oh my goodness, you're soaked! You need to get inside. Someone should get you a towel before you catch a cold!" etc., as I stood there all love-struck and speechless. He signed something for me, too. I still adore him
Finally,
Siouxsie Sioux and Budgie from Siouxsie and the Banshees. A bunch of friends and I were at a bar when we noticed them sitting in the corner. There was a lot of back and forth, but in the end, we ended up hanging out with them the whole night. I will never forget Siouxsie and I singing along with "Breaking the Girl" by Red Hot Chili Peppers, which was playing on the jukebox. It was an awesome night!
I've very briefly met
Jon Stewart (many years before he blew up),
LL Cool J (about 6 times -- we seemed to keep showing up at the same places),
Scott Valentine (remember Nick from Family Ties?!), a handful of other hockey players (all former NY Rangers)... I'm probably forgetting a few people. If I remember others, I'll post.