The game rocks, just the way the game starts and your first ingame words are 'gooo gaga dadda' already gives a sense of actually growing up in the gameworld.
The reason I didnt really got myself interested in the game was cause I played Morrowind and Oblivion and allthough those are very entertaining games, I didnt feel like getting a 3th of the (more or less) same game, but its far from the same game, eventhough the engine (afaik) is a redefinded version of Oblivions engine.
The game makes you think, no gunslinging and killing 20 badguys at a time. You'll get low on ammo quickly, stuff isnt all that easilly repaired and the combatsystem isnt all that forgiving like in the previous 2 games (Morrowing & Oblivion) where you could simply train your character if you had difficulties.
If this is remotely the genre of games you like, I really recommend you get it.
I will surelly get New Vegas when I'm finished with F3, which will take some time.

One of the most interesting things I found, compared to the previous 2 games, dynamic events.
Little spoiler about that below:
First time I got to the Super Duper Mart I found an event to play out, where my interaction set some events in montion .. I died. Reloaded and found a completelly different event to play out, no interaction needed, gunslinging for my life was needed (just 5 enemies of which 3 only had melee weapons).
I reloaded to see if the event would change or was just pick between those 2 events, I noted at least 6 different events to play out in front of the Super Duper Mart and thats cause after reloading a few times I felt like actually continueing my path, so there may be many more events that can happen.
I like that!

Many quests also seem to have a number of different outcomes (based on good or bad karma, or skipping parts, or taking the long route, etc).