Yes, this IS the daddy and don't you forget it. The single best and probably most modded game in FPS history. It's Quake contempory was great, vicious, organic and exciting given evenly matched players. Yet, still for me this game is the daddy. The latter incarnations or UT are also superb but it's still this with it's HUGE modding back catalogue (giving the game a massive amount of additional maps, mods and most of all replayability that wins the day. Damn I loved this game and damn it after all this time, I still do.
I still play it now, even with all the latter incarnations on my HD as well - just for the wonderful variety of maps and mods (Far too many to list here) - and they're still being made to this day.
Probably the best value for money purchase, if you like the FPS genre, you will ever make. Buy this and get umpteen new games with it due to the MODing community. You can't say fairer than that can you ?