I saw Van Halen (without Sammy) and thought they put on a great show.
I've also seen Korn, Metallica, Linkin Park, Deftones, Gravity Kills, Dave Mathews, O.A.R., System of a Down, Kid Rock, Powerman 5000, Puddle of Mudd, and a few others that I won't mention here (like Boyz 2 Men :jason runs and hides in embarrasment
All of them put on great shows, except I thought Deftones wasn't too great. Maybe they had a bad night, but it just sounded like everything was cranked as loud as it would go and you couldn't make out any of the songs.