Read the sticky post from that one thread. 560 ti is really nice. Let's say I'm aiming the highest detail setting for Skyrim, ultra of course. What kind of graphics card can do that?
Depends on the FPS you want, what resolution you want, and whether you want anti aliasing and anisotropic filtering. For Skyrim, the GTX 260 or AMD 5770/6770 is more than enough for ultra setting, 900-1080p resolution and modest antialiasing/anisotropic filtering because the game is CPU bound. If you really want good performance in Skyrim a sandy bridge quadcore CPU is a must. For other games, the GTX 260 and 5770 start lagging behind to medium settings at high resolutions like Witcher 2 and Metro 2033. The 560 ti is adequate for almost all games at High resolutions and High settings so is a good deal right now.
If you can't stand having anything less than 60 fps you need to go higher end, but there is a reason those people are called enthusiast.
Oh and disable Vsync in skyrim ini, or get d3doverrider to force triple buffering much better FPS.