New Vegas is more similar to the first two games, you may want to give it a try. 3 is horribly overrated and not much fun at all, in my opinion.
Actually now that I've given it a bit more perseverance Fallout 3 has become insanely fun. Yeah the combat's a bit clunky and the companion AI is abysmal but it gets better once you've leveled up a bit. Also, the usual RPG maintenance chores all but disappear after a few levels.
The story is fascinating and the world is just a joy to explore! I'm already lv. 17 with less than half the main quest line finished and God knows how many sidequests left to do.
I played NV and wasn't impressed. In fact I was utterly bewildered. Like Elder Scrolls there was too much to do to start with, no direction, and no capacity to sustain exploration or purpose to explore, nevermind that getting attacked every few steps is a hindrance to exploration, like in F3 early on when enemies are super powerful.
But, yeah, pleasantly surprised to find that I am having fun now! ^_^
/me goes back to blowing Super Mutant heads off ^_^