Fallout 3 will always be a 5 star rating in my heart. Fallout is my favourite franchise (with Metal Gear and Zelda) and Fallout 3 was my entry to the saga. But it's important to say that this game is not perfect and hasn't aged well. The setting of the Wasteland is magnificent - probably the best one - but the dungeons aren't good. There are a few exceptions (Dunwich Building, the metro), but in general in the dungeons there is no lore and there are just enemies to kill.
Now, because this is a little review of the goty edition, just a few words for the DLCs.
Operation Anchorage: pretty interesting, but not that good. God tier overpowered loot.
The Pitt: best DLC of Fallout 3. Great setting, great characters, great loot, best questline in the game.
Broken Steel: bad. With this DLC the level cap becomes 30.
Point Lookout: I always think that this DLC is overrated as hell. However, it's good and Point Lookout is pretty nice to explore.
Mothership Zeta: pure shit. God tier overpowered energy weapons.