Note: Pointfest is the local name for a summer radio tour. If you live in St. Louis, you know what I'm talking about. I can't remember the years, sorry.
Pointfest 3. It was my first concert, but would rank up there regardless. Sponge's lead singer crowd-surfed through most of their set and Bush had just put out Sixteen Stone.
Either Pointfest 5 or 6. One of them had a local band called The Urge that was on right before 311, and 311 was the last band of the night. They (The Urge) were so good that even my friends that were die-hard fans of 311 wanted to leave because 311 would just look ridiculous by comparison (plus, we were physically drained).
Deftones and Godsmack, 2001. The Deftones are one of the best rock bands out there, so of course they were just incredible. Godsmack's pyros were incredible. Their show was much better than I expected.
Tool, 2002. The only bad part was when the guitarist played the three notes from the end of one of the songs on Lateralus for literally 5 minutes. Seriously. Try listening to three notes over and over (they're very slow) for 5 minutes. It's insane. The rest was just incredible. And Tricky (the opening band) was also incredible. MUCH better than their CDs IMO.