Not every game needs to be EPIC to be enjoyable. Particularly sandbox games where you basically experience the world.
In a way too much EPICness can spoil a game, particularly if you think about it. For example, I love both Oblivion and Fallout 3, but how could someone who just crawled out of the sewers immediately save the world from Daedric invasion in Oblivion; or how can a 19 year old who just got out off an isolated vault dominate the wasteland and kill armies of Super Mutants and well trained Enclave soldiers.
...did anyone remember the behemoth inside the white house=EPIC....
There is no Behemoth in the White House in Fallout 3. Just Feral Ghouls. You are mistaking the White House for another location, which I won't mention for fear of spoilers.