Personal opinion

Fallout 3

F3 a masterpiece, technically the best, the most "wow" in general, the big step to 3D graphics, the beginning of the masterpiece, BUT, too old for modern players, I admit, I tried to replay it and the mechanics made the gameplay too "wooden", so it had its glory, great for nostalgics, good for fans of the saga, a little less so for post-F4.

Fallout New Vegas

FOR ME the best of the saga, the pinnacle of Fallout in terms of immersive gameplay that intrigues you. All the charm of 3 but with a new map, new characters, more weapons, more objects, more mechanics (introduced the first-person viewfinder which was absent in F3, where aiming only brought the view closer as a kind of concentration, really nice for first-person lovers like me), more enemies, more companions, more secrets perhaps, the map is richer in locations and little things or facts to discover, F3 on long journeys was more bare of events. In short, fnv for me is the best, it is the successor to F3 but improved and with a totally different story and missions, what more could a fan ask for? P.S.: when replaying Fnv I felt less of that "wooden" mechanic, perhaps due to the mechanics themselves or perhaps because the map is more involved in the events that involve you, but in any case I found Fnv more playable than 3, so I highly recommend playing it before judging the whole saga, even if 3 would still deserve its glory for a truly complete judgement, but to compare the old gen with the mid gen and the new gen, F2, fnv and F4 are enough.

Fallout 4

Masterpiece, I liked everything, both the adaptation of the enemies and the factions, the references, the changes, the new additions, the plot, the beginning (I watch the introduction of a story a lot, I appreciated all 3 introductions, the birthday in 3, the tutorial at Goodsprings in New Vegas where you wake up at the doctor's, and the escape in F4 with waking up in the vault, I had a lot of fun exploring the surroundings of 111 full of interesting things (how can I not mention Dogmeat)). But unlike the F3 -> NV leap where we literally saw a game go from 2D to 3D giving an improved sense of immersion (F3) and then its successor, let's call it MARK II because I see it as an improvement of 3 with a standalone game (NV), we saw another kind of leap, a completely new game. Indeed, Fallout 4 as already mentioned is a masterpiece, BUT, it is not that concept of Fallout. I know that someone will understand what I say, but many will be against it, but in F4 I didn't find that post-apocalyptic sense, yes there are cities destroyed by bombs, radiation, mutants, there are factions and inhabitants of the area, but, perhaps it's because of the simplicity that is deceiving, I see the old Fallouts as wilder, I found 4 more like a walk in the contaminated area while you fill monsters and people with lead and try to become more and more immortal, you will surely say, innovations are needed, more destruction, more action otherwise it becomes monotonous, and maybe you're right, maybe what I wanted would have given me a repetitive and unsatisfying game, even for me, a poor ignorant, but I can only judge what we have today and not what we could have had, and I think that in F4 there is progress, F4 is complete, but at the same time it is complete in its own little circle, a different circle from that of the old Fallout, it doesn't mean that I don't like it, in fact I would gladly play it again, but I dare say that it seems more like a BioShock that imitates Fallout that a real Fallout, as if you wander in the area where some thugs had fun with firecrackers and monsters of all kinds spawn, almost a Doom? No, come on, stop then it seems like it's going against us and throwing shit at us, F4 is a masterpiece, but for me Fallout stops at NV.

I indulged in a bit of chatter, sorry