1) Fallout 2 is a fine game. But as a sequel to Fallout it is sorely lacking in, well...Post-Apocalyptia. I get that society moves on, but things got a might too civilized too quickly. New Reno springs immediately to mind in that regard. As for rehashing the original....it pretty much recycled the premise of the first game. Shadowy menace from out of the Wasteland needs non-irradiated Humans for Reasons.
2) New Vegas is a boring desert (Thematically appropriate for the setting). But its true crime is that 90% of the buildings you do come across in the Mojave are boarded up. They're not small buildings either - there's an entire apartment complex by the REPCONN Headquarters that is just eating up real estate with no intrinsic value. New Vegas commits the ultimate sin in this regard. In addition to barely giving anything to sate one's wanderlust...it teases and taunts the player of locals of interest that are completely sealed off.
3) Fallout 3 was the successor of Fallout 1, in much the same way New Vegas is the successor to Fallout 2. As I prefer Fallout 1 to Fallout 2, it stands to reason I hold Fallout 3 in higher regard then you do, given your preference for Fallout 2 and New Vegas.
The best thing about that?
There's room enough for everybody in this franchise. You personally don't have to enjoy the same things I do in the Fallout games. There's plenty enough for everyone.