oasis789: I am torn between RPGs and adventure games
Neverwinter nights, BG1/2, Icewind Dale 1/2
Psychonauts, beyond good and evil, fahrenheit, under a kiilling moon
argh
Why not get the best of both worlds? Makes for more variety, too.
Like Psychonauts, Beyond Good and Evil, BG(1/)2. And/or Neverwinter Nights for the huge amount of great custom content (with regard to gamelength, the BG series and especially NWN are more than enough for several months).
Of course, it all comes down to your preferences. The games you list under Adventures are very different from each other. All have their strong points and are worth checking out. Fahrenheit has great atmosphere and could be an excellent adventure but I found the the Quick Time Events really annoying and immersion-breaking - and they're a fundamental part of the gameplay. (I didn't get very far yet.) UaKM is a cool P&C adventure but it suffers partly from the typical weaknesses of the genre (pixel-hunting, obscure puzzle design, not knowing what to do). Psychonauts can be frustrating at times, but IMO of the three it has the most varied gameplay and the most original ideas, therefor it was the most motivating for me to play. To a slighty lesser extent, the same goes for BGE.