Yes, I've played Halo 2. Halo 2 had the longest campaign, by far the best soundtrack, new additions like boarding vehicles and players could use the energy sword, good ranking system, the most addictive multiplayer of the series, great maps, the campaign ending was a cliffhanger but it set up Halo 3 perfectly and was epic, the Halo community was in it's prime, fun glitches, super jump, yes weapons like the sword and needler were overpowered but in a way that just made the game way more fun, and when everyone played fairly (not using BXR, etc) it was beyond ridiculously fun.
[Edited on 12.23.2012 4:06 PM PST]