Fallout: New Vegas is one of my favorite games ever. I would probably rate Fallout 3 a fraction higher but that's mostly because I liked the atmosphere better and, probably, because of nostalgia. New Vegas had superior writing, better quests, a much improved environment, and a lot more content.
Unfortunately, it also had the EXACT SAME bugs as Fallout 3. Bethesda did nothing to fix the engine. They just handed it over to Obsidian. Still, it's worth the bugs. I have hundreds of hours into each one, I just save constantly.
It's also, in my opinion, a PC game. There are mods that fix things, mods that add awesome content, and mods that just make it a better experience. Using a PC also allows you to quick-slot ten weapons, which I abuse often.
Fallout 4, when it's announced, will be my most anticipated game, period. All they really need to do is get a better engine, fix the bugs, and give us more content like FO 3/NV. I'll buy it Day One.