I think vtuner2 would be for your motherboard/CPU. I might be wrong though. I don't think thats the one for your video card for instance.
Lurkswithin has given some good examples there. ATi Tool for example is the best one available for ATI cards, though I find that it has no distortion on the image, but when you play a game, theres loads...
The best one if you had a Geforce card for example, would probably be CoolBits, but I haven't used this to know how stable, useful it is, etc.