Oh yeah I loved playing Halo 2 when I was a youngster. Fun stuff, played like 5 hours total though.
I've played some online as well, that was fun, but still only Halo 2.
I played some of the first Halo at one time too, but I couldn't even understand how to write "hi" in my mother language at that time so yay.
I never understood anything about it until at a later age, but I had grown this dislike for the FPS genre and especially mainstream FPS games at that time, so seeing the release of Halo 3 got me thinking "... meh.". I've never actually bothered with it since then, shame since it could've been fun to go back to.