What posessed you to bring in level caps?
Fallout 1 had a level cap of 21. Fallout 2 had a level cap of 99, but the game only provided enough content to get to level ~23 or so, with the only other sources of XP being random encounter farming and the hintbook/vault city cheat terminal after the game, both of which were a joke.
What happened to the G.U.R.P.S system?
Fallout 1 used SPECIAL instead of GURPS because of legal issues. If you were hoping for this game to use GURPS, you were hoping for something that has never ever been in a Fallout game, not even Fallout 1.
a poorly thought out and rushed story line that just wasn't as broad or forgiving than you made it out to be, a terrible ending no matter which way you do it - still being forced into narrow, crappy story lines... I actually prefered just mindlessly running around and having nothing to do with the storyline. This game had so much potential to make up for the mistakes of the last one, but all you really did was give it a shiny new coat of paint and a few new accessories
Poorly thought out? Narrow? What? Compare New Vegas' plotline to Fallout 1 and 2's and you'll see that NV's plot is considerably less narrow than, say, FO1's and 2's. Seeing as how both those games only gave you one option at the end rather than four.
Edit:
On a Microcosmic level the FO Vegas writing is better but in the Macrocosmic level FO3's storyline was superior, ok you are trying to save the entire wasteland and purify the water for everyones benefit, Epic! I got shot in the head, lets chase those bad men down. mmmmmmm which was an overall better storyline???? Vegas does bring back that old FO feeling I'm sure but really FO3's Epic storyline is crap? ha ha ha ha ha

Fo3's "epic" storyline is crap because it's dumb and contrived.
You can filter radiation from water with [censored] dirt and cloth, both of which are in common supply in FO3. A robot you're given as part of a housewarming gift can get purified water from condensation.
Your "father's" sacrifice is dumb and out of character ("I'm willing to sacrifice my only child and link to my beloved wife on the hope that maybe he'll/she'll be able to clear the purifier of creatures famous for treating power-armored soldiers as canned cram so that I might turn it on. [five minutes later] ZOMG, Can't let these other guys turn on the purifier! Yays sabotage!"), and the ending was full of retardation from the rad-immune companions to the fact that the game throws anti-radiation countermeasures at you, to the fact that Liberty Prime, while cool, basically turned the climix of the game into an interactive cutscene.
Compare New Vegas:
You're a courier, you're shot in the head and so you continue after the guy who did it either to get answers, to recover what was taken, or simple base revenge. When you get there, you're drawn into a power struggle to decide the fate of everyone in the southwest. Do you support the NCR, the government with good intentions but crushing bureaucracy and inefficiency? Perhaps Caesar, trading liberty in exchange for discipline or safety? Or do you support the enigmatic Mr. House, who wants to rebuild the world the way it was, with all its technology and social flaws? Or do you feel that your firm hand is the one the wasteland needs?
DC hasn't made much progress at all in 200 years. Given how nobody knows how to filter water, I'd be surprised if there was more than a hundred thousand people in DC. Out west we've got actual organized societies. The NCR as of Fallout 2 had 700,000 people, and they've only expanded since then. Caesar has 87 tribes underneath his banner, and is implied to be even larger than the NCR.
So yeah, I'd say that NV's plot is way more epic than Fo3's, if only because Fo3's plot only works if everyone is an idiot.