Fallout doesn't seem capable of holding my interest, and that goes for the entire series. Although admittedly I have spent very little time with 2 and none with 1, I imagine there must be a reason I stopped playing 2 shortly after starting, twice. Occasionally I'll get like "yeah, awesome!" about it and get pretty into Fallout and then just stop sometime later. I think I dislike its relatively self-conscious tone and/or sense of humour, but enjoy the narrative themes. The one I like most is New Vegas since it seems so... alive, I suppose, like everyone genuinely gives a **** in-universe for once.
I like FO4's soundtrack and not a whole lot else. The graphics look weird, like the same sort of low-res washed-out look Dishonored has, and in FO4's case it doesn't suit. I want to see that two centuries of accumilated grime in detail, damnit! The insanely limited and insufficiently labelled ME-style conversation options and voiced protagonist who rarely says what I expect and never says it how I would served to kill off my waning interest. I like the combat to an extent and, uh... that's pretty much it. Playing STALKER would be a better experience, considering that. I had no interest in the settlement thing to begin with, but perhaps I should give it a shot with a new character, since the idea of rebuilding society and establishing some manner of economy is actually a fairly interesting direction to take a post-apocalypse setting in a video game context (though, generally speaking, it makes perfect sense and isn't remarkable). I'll wait for patches, though. Also, small thing, but I can't help but notice how much more common pre-war money is in this game compared to previous ones. Strange, considering how its caps value has gone up.
FO4's guns often share reload animations which bothers me especially because every gun is left-handed. If they think they need to animate left-handed weapons to put more on the screen, they need to watch the Dragunov reload from CoD4 on a loop and take notes. I remember reading on TvTropes once about how Obsidian did guns realistically (with regard to visual and sound design) well in NV because at least a couple of the guys worked with guns in the past, or something. Every time I think of the hunting shotgun I start missing it.