Battlecross
Banned
I don't know, maybe the transition in FO1 is "forced" in a way, but by that point you had many encounters with the Mutants and the Children of the Cathedral so they don't come out of nowhere. In FO2, you also have a lot of opportunities to see the Enclave doing their stuff before even getting the GECK (You can even get to their base), in New Vegas you don't even need to focus on the revenge thing at all, you can even complete the entire NCR quest line without talking to Benny and you experience both big Factions on the way to Vegas.
In FO3 tho, the Enclave are virtually non existent outside of their radio station and you can't even talk to the BOS before the attack on Project Purity.
Don't get me wrong, the plot in Fallout 3 was horrible. I just felt that the the events somewhat fitted more with each other.
In Fallout New Vegas, I found it strange that as soon as you are seen exiting the Lucky 38/Tops, all factions somehow want you to do all their work while you're just a nobody they have no reason to trust. In Fallout 1 and 2, you influenced the fate of post-war societies too but it was usually by a certain chain of circumstances, while I felt that in NV, the factions basically say to you : You're the main player, decide the fate of everyone.
This makes complete sense with the Yes Man and is okay with the the other factions questline too, but their overreliance on you seems a little forced.
Unfortunately in all these games that want you to be a "nobody" that you can become as the player tend to have weird things to make them work in the story. FO3 and NV both have this issue where you're like a big player in the story but you're not really because you're a mute who only converses through text and people love/hate you based on distant actions, it's all weird. I'm guessing this is why Bethesda went the voiced protagonist route this time which I am not hugely happy about, but we'll see how it plays out. Could be worse or better, I don't really know.