I never player Halo 2 multiplayer, but both me and my brother loved Halo: Combat Evolved multiplayer. Was awesome back in the day (I played it on a Mac, by brother probably on a PC).
In my opinion it was the best FPS that I played, I'd put it above Unreal Tournament, Quake 3, Doom & Marathon.
However, at some point it seems there were many aimbots in the game, which ruined the gameplay for me.
I think we can all agree it's multiplayer was better than the current halo infinite.