Absolutely I enjoyed F3 more than Oblivion. This was due to 2 things:
1) Fallout 3's world has CHARACTER. It isn't just a wide expanse of forest with very few towns in between. The characters, voice acting, factions, monsters, weapons, locations, and established setting are all far more imaginative than what I found in Oblivion.
2) Completely re-worked scaling system. Like Oblivion, enemies scale up with you, but unlike Oblivion, it doesn't becoming immensly frustrating after you get to a certain level.
Fallout 3 is just far more enjoyable than Oblivion. Of course, I understand that Oblivion came out long before F3, and thus, couldn't have been as "content packed" as F3 was. Still, the landscape in F3 is just far more visually interesting, with it's ruined buildings and cracked roads and partially destroyed houses. The little clues they left as hints to how the pre-war world functioned was also neat.
Even though F3 is better than Oblivion, in my opinion, Oblivion does have some advantages over F3 - namely, larger (if blander) world, more quests, longer play time, and usually more ways to do things. F3 was great, but it wasn't really a role-playing game - you had to learn small guns or you'd have a MUCH harder time getting through. And all quests usually had either two ways of being completed: Kill everything, or Kill everything until you get to one guy who you can defeat in a ridiculously easy and completely unrealistic speech challenge (seriously, one enemy in F3, you know who it is, can be convinced, despite EVERYTHING HE HAS DONE, to kill himself just by saying one thing to him, along the lines of "hey what you're doing is bad, you know that", and he responds in this fashion "oh, guess you're right, better off myself despite all those years of hard work following my goals"). At least Oblivion had multiple ways of completing some quests and some "true" stealth missions.
