Ozzfest - Only listing bands I actually remember from the shows
2000
Ozzy Osbourne - It's all about the water show
Pantera - RIP Dimebag
Godsmack - Killer show for only having 1 album out at the time
Static-X - Is that a slim jim
Incubus - fuck them
P.O.D. - ghey
Queens of the Stone Age - not really my thing
Kittie - want to pet the kitty
Taproot - meh
Black Label Society - Someone take the fucking mic away from Zak
2001
Black Sabbath - duh
Marilyn Manson - freaks everywhere
Slipknot - It's like gwar with decent music
Papa Roach - meh
Linkin Park - Didn't see them.  Too busy staring at lesbians going at it right in front of me
Disturbed - I like them and all, but live was only ok
Spineshank - They are not terrible.  Have seen them with Type O too.
Hatebreed - very evil
Otep - Creepy thinking sounds like that come from a chick that hot.
2002
System of a Down - I hate them almost as much as their fans
Rob Zombie - very stripped down show, but not bad
Drowning Pool - Sound was all fucked up
Down - 2nd stage, didn't know much about then when I saw them, but decent
Soil - These guys were awesome.  Too bad he went to drowning pool
Andrew W.K. - Fuck him
Summer Sanitarium
Metallica - I wish I had seem them before St Anger came out...  Still awesome though.
Limp Bizkit - Came out and played break stuff and hot dog right away and got people in a fighting mood
Linkin Park - fuck them
Mudvayne - Missed most of their show, since they were on first, but sounded pretty good.
Deftones - This was right after he claimed they were carrying the show, so the fans were pissed the whole time
Other
Type O Negative - Seen them 4 times.  They never disappoint.
Clay People - Open for Type O.  Local industrial metal band from Albany, NY, but had moderate national success.  It's a very different sound.  
Corrosion of Conformity - Caught them headlining a metal show with Soulfly, Puya, Stigmata.  Not bad, but I didn't know much about them before I saw them.  Still cool.
Godsmack - Ozzfest show was better, but saw a lot of underage titty
Breaking Benjamin - open for Godsmack, meh
Aerosmith - Need I say more
Kid Rock - opening for Aerosmith.  Better than expected
Run DMC - opening for Aerosmith.  Didn't know they were on the tour, so I missed almost all of it.  They did come out to play walk this way as an encore.  Doesn't get much better than that.
Nickleback - Wife dragged me to it.  Much better than I would have expected.  Chad Kroger has a thing for Pantera, so he fills time playing Cowboys from Hell while they fling beers into the crowd
Puddle of Mud - Decent for a whiney chick band
3 Doors Down - Fucking green lasers.  What is this, 1983.  If I want green lasers, I'll go see...
Poison - I love green lasers
Warrent - Jani Lane and a bunch of other guys.  Fuck, is he bald now?
Quite Riot - Only saw last two songs, but the happened to be cum on feel the noise and metal health
Maceo Parker - Sax player for all the legends of Funk.  P-funk, James Brown and down the list
I am sure there are a lot more...