So far the game I have thought worked really great, with a good 3D effect and acceptable framerate and usability:
Skyrim
Morrowind
STALKER games
Farcry 3
Fallout 4
Ive found that I am most comfortable in the virtual cinema, with the screen as close as possible, with headtracking enabled. It still feels like Im in VR, and I can always look down and check the HUD easily. I usually completely forget that I am in the cinema, and it works great for keyboard and mouse use. All of my experience is basically directed at this type of use. Here are some other games I have tried that Ive enjoyed, but have some minor drawbacks from my testing:
Outlast: This game works great, but I find that Geometry mode creates weird shadow issues, and on other 3D settings there are some minor graphical issues. Its not bad, and totally playable. on z3D modes, it seems like there could be a little more depth with the 3D slider.
Oblivion: Slow on G3D, Z3D modes dont seem to give quite enough depth that I would like. Game still looks great, and is very playable.
Portal 2: Something just does not look right in this game. Im not sure what it is, but it looked very very wrong when I tried it. I might try it again, but the first experience really put me off.
I may have forgotten some games that I have tried. So far I have been very impressed with VorpX!