aTuner is an easy-to-use tweak-tool for GeForce-, Quadro- and Radeon-graphiccards:

aTuner Features
Full hardware- and driver-detection
Support of any common 3D-hardware from ATI and Nvidia
Supports up to two monitors on an Nvidia-card via Windows dualmonitoring, TwinView and nView.
Shows all important 3D quality-settings in a single window
Support of the un-official modes, too
Shows the most important settings even in the tooltip from the systray
Easy-to-use alteration of all Bequeme Änderung aller relevant tweak-optionen without to have much click-around
Self-explaining usage
Does not unnecessarily writes in the registry, but offers a log of all write-actions into the registry.
Profil-Managment
Game-Launcher
Sys-Info with focus on display devices
Designed to be friendly to other tweakers, like RivaTuner
Regular support through the author (fast adaption for new drivers)