WELCOME TO QUAKE III ARENA
One of the best arena shooters out there.
Online community is anything but dead and ready to destroy your ego with raw skill.
Weapons are well balanced, maps are well designed, and there's tons of community made maps/mods out there for you to try.
Being an arena shooter, you're not just focusing on pumping your opponent full of lead, plasma, and rockets, there's a lot of depth to the game, like item/area control and you will need to keep these in mind or else you're toast.
Sadly QuakeLive appears to have done away with these concepts to try to attact a more casual audience, thankfully original Q3A is still alive and well and doesn't look like it's going away anytime soon.
Rip and tear!