A puzzle game that does really test your video card but only if you choose multiple connections of the items, it's much like bejewelled but more intense. It's called
"The Curse of Montezuma" and usually crashes toawrds thae last few puzzles.
Using the bombs and other extras to clear masses of objects seems to be the worst of worst however, if you don't use them and only use the connect of 3 or more objects, it doesn't take as many resources.
I played it on Windows 7 x64 8gb ram with a GT560 video card (and 850 watt PSU).
It costs about $10 retail.http://www.alawar.com/game/curse-of-montezuma/