Oblivion and Fallout 3 are incredible. Far superior to Fallout: New Vegas as far as I'm concerned.
I don't really know how anyone can honestly say they liked Fallout 3 more than New Vegas. New Vegas had so many more options it was ridiculous, not to mention there were actually challenging enemies. It really shouldn't surprise people that the company (for the most part) behind the first 2 Fallouts made a better Fallout game than Bethesda. I don't hate FO3, I enjoyed it quite a bit really, (minus the ending) but FO:NV was much better IMO.
TES has always been my favorite franchise though, so I am biased and I do think Oblivion was better than both of them. I also think Skyrim will be better than all of said games, and I am not worried. The only thing I've seen I was even slightly disappointed about was the map, and that isn't a major problem.