Yeah I'm going to get flak for this, just as I got flak for not liking Half Life 2. Though, It should be a counterpoint to those people that I have enjoyed similar games such as S.T.A.L.K.E.R 
 
Fallout 3 was nothing that it was hyped up to be. Immersive? No. Expansive? No. Satisfying Campaign? No. They basically took the postapocalyptic open world idea and boiled it down to its most mundane aspects.  
 
The gunplay is terrible, with the only viable option being to kill people with VATS. VATS seems rather like cheating, and gets boring fast anyway as you essentially just rush up to people with a shotgun and shoot them in the head, no matter what the enemy.  
 
Presentation-wise, the voice acting was meh and the graphics look terrible. It looks like it's running on first generation Source Engine or something; I played the PC version with everything cranked up to max (including res and AA) and that didn't help. Not only is the game graphically lacking, the artistic style is ugly as well. Open world games are supposed to compel you to explore, who wants to explore a land the color of vomit?  
 
For an open world game, it's actually quite small. The vast majority of explorable land is simply empty with a couple wild beasts scattered here and there. For an RPG, the game is also incredibly short as I finished it in 7 hours while doing a reasonable number of sidequests and speaking to most people I encounter. Compounding to this was the infamously bad ending, one of, or possibly the least satisfying ending I can think of in all my years of gaming.  
 
Fallout 3 could've been great, but the execution was extremely clumsy. After playing games like Mass Effect and Stalker, Fallout 3's lack of atmosphere, lack of features and poor visuals was made pointedly obvious.