Funny you mentioned Oblivion, as I looked at it a hour ago. What exactly are the series? 1st person 'shooters'?
Elder Scrolls is the series, it's a first person sword/axe/mace/bow/magic game. Open world, can go anywhere you want, do quests, hunt animals, pick up anything you find and sell it. Tons of stuff. They're mainly PC games, but Elder Scrolls III: Morrowind was brought to the original XBOX, then Elder Scrolls IV: Oblivion came to the 360 then PS3 a year later. Elder Scrolls V: Skyrim was pretty much made for consoles in mind because of the menu systems.
Same company that made those games made Fallout 3.
Oblivion- medieval like, swords, goblins, elves, stuff like that.
Fallout 3- post apocalyptic world, guns, mutant creatures/humans, stuff like that.