Too many to count with Fallout 2. I still prefer it over the original, but only because of the greatly expanded role-playing elements. Combat for the first 5-6 hours of the game is a complete chore, and there's a lot of situations where you're better off just running.
Temple of Trials is...
I'll start with some background. I picked up vanilla New Vegas off a recommendation from a friend. Partially because I wondered what the big deal with all this "Fallout" stuff was, partially because an open world RPG set in a post apocalyptic version of where I lived sounded like the best game...