I'll be honest - I've never been much of a computer gamer, especially for the last decade or so. I still love to break out Quake III for a few hours, because my old computer can't handle many newer games. I played Fallout 1 and 2 many years ago, but lost the discs in a move and never got around to replacing them. But a year or so ago I got access to an Xbox 360, and the first game I got to play was Fallout 3.
I loved it.
Yes, it's glitchy and buggy in many spots. Yes, the story is basically a shooter on rails, especially at the end of the main game. Yes, speaking characters look like animated zombies with zero expression. I've never played Oblivion, never dealt with other Bethesda games, so I can't say whether they are good or bad. But I still had an awful lot of fun with FO3... for a while.
After a couple playthroughs, the shine wore off. The acting got old, the quests got tired because you had to do most in the same order. The ending had almost no variation. The DLCs were an improvement, but ultimately unsatisfying in different ways. Mothership Zeta and Anchorage were basically rail shooters, and Point Lookout was just whacked out. The Pitt was interesting, but even then there were only two paths to choose. Broken Steel, at least, let you see some of the consequences of your actions in the main game.
I think FO3 revitalized the franchise, brought new gamers into the Fallout world, and paved the way for better games (hopefully a series of them). It also has a lot of good gameplay, at least for me. Despite all its flaws, it's still a good game. But one of the top 10 of the decade? I really can't say.