I'm recomending not just NV, but the entire Fallout franchise. Both FO1 and 2 are awesome old school point-and-click RPG, don't take long to finish (I finished 1 in 9 days playing 3-4h/day), but have great story and memorable characters.

FO3 and NV are FPS/RPG, both with huge worlds, fully voiced, good story, but the best part is the countless quests and sidequests, the ability to just explore every part of their worlds, discovering the history of each place.

A must franchise for RPG fans. Go buy it, NOW!

Excellent Co-op Survival Shooter, a must for Left 4 Dead fans.