Tribes came out in '98, too. Its sequel came in around 2000, so you can mark that down as something worth playing during '00-'03

There's a bunch of doom knockoffs (Hexen, that RPG thing in the Doom engine, etc, etc, etc.) that could probably stand to be in there somewhere. I also see no duke nukem 3d, which is a serious gap. '96 for that.
But yeah, the progress that's occurred is quite amazing. It's not really a surprise that things are slowing down, though. I'd probably say there's just not really much else to
do for pure FPSes until, I'unno, brain jacks or something. The field's kinda' saturated, and short of mixing it with other styles of play (which is where a lot of them go nowadays, from what I understand), most things have pretty much been done.
On the bright side, we're probably only a few decades from hitting the straight wall of hardware doubling, which is when things will probably get
really interesting. Our machine overlords will give us new and even more interesting FPS games