I don't think it's the lack of an inspirational game, I think it's being over saturated with FPS games, and being blessed with many good games.
As you well said, Goldeneye was ace, not just because of it was a brilliant FPS (it was... absolutely), but because it had no competition what so ever (in real terms).
Now take a look at the current market. In terms of FPS you have:
COD4 - Which is the leader.
BFBC
Halo 3
UT3
RB6V2
Gears of War
Condemmed
Ghost Recon 2
Darkness
All which are hugely popular and great games in their own right. If any of these games came out at the time Goldeneye did, it would make the same kind of impact (ignore graphics and power, we're talking hypothetically). That is the difference.
We're in an age where we're blessed with so many GOOD games and games where if released in the past would have been great games. It's more over saturation, rather than lack of quality in my opinion.
But you are right, we do tend to move away from games a hell of a lot more, this is down to new games being released every week in the same genre in my eyes.
Take WoW as mentioned above, yes it's a GOOD game, yes it encorporates a lot of different aspects which haven't been seen before, but there is no competition.
The closest I can recall (and I'm not a huge MMORPG fan), is when SWG was up against DAoC. And that was a while ago. If MMORPG had the same saturation as FPS games, then we also wouldn't play the same MMORPG all the time. Some days, you'd fancy being a jedi, the next a mage, the next an ogre and so forth. The same applies to the different environments within an FPS.
Also, I do believe the ranking systems within FPS now (COD4, Halo and BFBC) are trying to combat this over saturation and give you a goal to aim towards, just so you will play it longer. Rankings to at least half ofo us, mean nothing. But it is something to aim towards definately.