Too hard to list just five...
BEST 5 FESTIVAL SHOWS
US Festival (3 days - Headliners: Van Halen, Clash, David Bowie - also performing were Ozzy, Scorpions, U2, and 50+ more bands)
Tibet Freedom Concert (2 days - Headliners: Red Hot Chili Peppers, Rage Against the Machine, Smashing Pumpkins, Beastie Boys, Sonic Youth, Bjork)
A.R.M.S. Concert (Multiple Sclerosis benefit for Ronnie Lane) - featured performances by Eric Clapton, Jimmy Page and Jeff Beck (who all performed solo then came out for a jam). Also included Stevie Winwood, Joe Cocker and Paul Rodgers)
In Concert Against AIDS: Grateful Dead, Tracy Chapman, John Fogerty, Los Lobos, Joe Satriani, Tower Of Power
Peace Sunday: Very eclectic performers - included Croby, Stills, and Nash, Bob Dylan & Joan Baez, Stevie Wonder, Tom Petty, Jackson Browne, Linda Ronstadt, Stevie Nicks, Bette Midler, Bonnie Raitt, Donovan, Dan Fogelberg.
BEST 5 STAGE SHOWS (Visual)
Pink Floyd
Rolling Stones
Depeche Mode
U2
David Bowie
BEST 5 METAL SHOWS (Headbanging)
Metallica
Scorpions
Van Halen
Ozzy Osbourne
Judas Priest
BEST 5 CONCERTS I WAS AT THAT WERE MADE INTO AN ALBUM
Scorpions - Tokyo Tapes
Judas Priest - Unleashed in the East
Bob Dylan - At Budokan
Cheap Trick - At Budokan
Grateful Dead - Okay, not really an album, but I have great bootleg recordings from several shows I attended 
MOST MEMORABLE PERFORMANCES:
Bruce Springsteen and the E Street Band
U2 free concert at San Jose State
Jane's Addiction at Lollapalooza
Talking Heads (Stop Making Sense tour)
Neil Young at a Bread and Roses show at UC Berkeley in the fog
COOLEST TWO BAND LINEUPS
Page/Plant w/ Stone Temple Pilots
Tom Petty w/ Bob Dylan (the Heartbreakers played back-up for Dylan...best    Dylan show ever, and then Petty and Dylan played together)
Nine Inch Nails w/ Marilyn Manson
Black Sabbath w/ Blue Oyster Cult
Mahavishnu Orchestra w/ Jeff Beck (Blow By Blow era)
BEST 5 SOUND
Yes
Jane's Addiction
Depeche Mode
Pink Floyd
Suzanne Vega
BEST 5 SURPRISES (Didn't expect much, but was blown away)
Roxy Music (Avalon tour)
Police (first US show)
Pretenders
No Doubt
Tie: Fleetwood Mac, Erasure, REM, Primus
BEST 5 JUST PLAIN FUN SHOWS
Oingo Boingo
Stray Cats
George Thoroughgood and the Destroyers
Santana
Fishbone
BEST 5 SING-A-LONG SHOWS
Police
Depeche Mode
Cure
U2
CSN&Y
Damn, I could go on, but enough from me for now - thanks for the memories...
ADG