And that's why I gave up playing computer games at all. Doom was fun, Duke Nukem 3D had its moments but by Quake, I'd had enough. As far as I was concerned, it was just the same game again and again.
I got very bored of the "Ooh, look how good the graphics are!" every time a new game came out. Personally, I think games were better when the machines were more limited and programmers had to work with what was available, they pushed the hardware as much as they could, then spent the rest of the time on gameplay. Whatever happened to gameplay, eh?
It's still there, you just choose to ignore it.
Long before you "gave up", there were innovations in gameplay in first person shooters. Ultima Underworld (which predates DOOM) and Ultima Underworld 2 were both fantastic RPGs which melded the RPG and FPS genre. System Shock took it to an even higher level, both graphically and gameplay wise. Yes, there was a drought between Quake and Quake 2, but then came Half Life with its rich story-telling. Deus Ex, the Elder Scrolls games from Bethsoft, again, upping the RPG ante, and in '04, Half Life 2 with its incredible physics engine (not to mention the even deeper story). And if you missed Portal (and the upcoming Portal 2) you probably missed the game of the decade.
There's plenty of fun and innovation to be found in first person games. Not all of them are made by iD, and not all of them involve running from one room to another picking up ammo boxes. Although done right that's plenty of fun as well.