After a buildup I run memchk86 overnight, run prime95 overnight the next day, and in between I run whatever 3dmark version was current when my vid card came out. I don't care about the absolute number of the 3dmark results, but if it runs without crashing and the results are in the general ballpark for similiar computers in the 3dmark results database, then I figure nothing is really messed up. If you get 3dmark scores 20% or so below everyone else though, then that's a good clue that something isn't working right.
I agree about AH being a good test... If it runs AH without crashing and you get decent performance, then it's ok.