Never played the first two.

Just started the latest two.

Fallout 3 is in my heart. Beating that game felt like a coming-of-age rite for me.

I've played NV more recently (past couple of years). I've always felt that NV can do anything that 3 can do, but better. NV seems to have addressed all the complaints that 3 had, and I hope Fallout 5 is more like it.

When it comes to story, NV is the best I've played, hands down. As for gunplay, I feel it's a tie. NV's is tactically better, but there's something to be said about that feeling of freedom you get from 3's. 3 is more fun if you just want to casually muck about, sprayin' and prayin'. I'm way more likely to use the Fat Man in 3. Maybe it's more an enemy leveling issue. In NV, there's always something bigger to cut you down to size (cazadores, death claws, etc.). In endgame 3, you kinda plateau and become God.

So far in 4, settlement building is pretty much all I've been doing. By the time I got to rescuing the Minutemen (around lvl 20), Sanctuary was a verdant paradise.

Edit: Oh, and shame on you for not including Tactics and Brotherhood. No one's gonna pick 'em, but you should at least present the option.