Not something that comes up much, but yes there are games that need more than 1gb vram to play smoothly (at least what I consider to be smooth).
I had 2 6850's in crossfire 1gb each (1gb total useable vram as crossfire mirrors the memory in moth cards). and i noticed what i thought was microstuttering, in skyrim and crysis II, both with high quality texture packs on.
MSI afterburner always showed like 997 or 998 mb used, so i thought, cant be maxing the vram, must just be crossfire microstutter. But then i get my gtx660 2gb, and is more like 1200-1300 MB used vram on the same settings, but everythin is rock solid smooth. So i guess the 6850's must reserve a couple MB's. So what what i thought was microstutter was probably just lack of vram, and the overflow goes to system ram, since all other games seemed to play smoothly that were'nt near the vram limit. I know bf3 will max out 1gb ram also. So i probably wasnt actually seeing any microstuttering at all, just maxing the vram.
So i guess this means the new era of video cards needs 2gb, or at least more than 1gb to max out new games. Hope this helps some folks and others can contribute to the list of games that flow over 1gb.
Ya I think it's safe to say that if you play on 1920x1080 or higher you want a GPU wih 2GB vram for maxing out the latest games smoothly. And if you're using multiple moniters you want more vram of course.