Well I spent about 15ish hours in Fable II and 35 in Fallout 3 on the first play through. The main difference is that while the main story is kind of short for both games, Fable II's extra content is mostly a whole bunch of minigames, money making, marriage, etc. Meanwhile Fallout 3's is other actual stories, quests, npcs, and generally I found it far far more interesting than Fable II's extended play.
That said I recommend you Fallout 3, it's a far better game imo.
Tag(thx fkusumot) - "Yet again I completely fail to see your point..."
HD vs Wii, PC vs HD: http://www.vgchartz.com/forum/thread.php?id=93374
Why Regenerating Health is a crap game mechanic: http://gamrconnect.vgchartz.com/post.php?id=3986420
gamrReview's broken review scores: http://gamrconnect.vgchartz.com/post.php?id=4170835
