I think you'd actually find a P2 with a Riva TNT set-up would be rather less fun than you think, no matter how far it was pushed.
Remember that although a lot of code is lazily written for the big games, the hardware has a very efficient design. That's why games still look so good.
I think you're absolutely bang on about modern games being boring - the only PC games I buy are ones with "Civilization" and "Red Alert" in the titles, these days - but I think you're misplacing the blame.
It's kind of like saying that modern chart music is rubbish because we have CDs now. It's not, it's because chart music (and PC games) have become commodity items rushed out by large corporations for as little time and money and as large a return as they can garner. The fact that PCs are very powerful is nothing to do with the quality of the game - there's nothing to stop a coder writing really efficient, powerful code on an i7 - but even if he did that he might get a few frames per second more.... and a few fps more does not a good game make. In other words, instead of rubbish running at 60fps, he'd have rubbish running at 63fps.
That's why I have a PS3 for the occasional bash of Warhawk or Skyrim, and I have Amigas, C64s, Sinclairs, the rest... for when I actually want to play something new (to me).
Luckily I have a really interesting PC. It's my bridgeboard in my Amiga. It plays UFO: Enemy Unknown and Ultima VII, and that's all that matters.
