I haven't played Oblivion since I played FO3. I got to Oblivion very late (my computer couldn't handle it when it was released) so it wasn't long after finishing Oblivion that I played FO3. FO3 had a markedly more refined engine and I knew it would be difficult for me to go back to Oblivion. I did enjoy Oblivion, but I never played enough to develop a deep attachment. I wouldn't rule out playing Oblivion in the future, but I do think it's unlikely.
Overplayed both Daggerfall and Morrowind as in stopped playing Morrowind then I picked up the mushrooms needed for an early mage guild quest in the starting town and did not remember that I did it, it was automatic like locking your door. Still plays Oblivion to test out new mods but fells I’m done with it.
Fallout 3 was an excellent game, played it a couple of times however never liked the setting as much as elder scroll. Add that the limited selection of weapon and armor at fixed locations limited replay value. Recon armor, vengeance for heavy weapons, fatman to make pack of reavers go away, Old faithful, Lincolns repeater and a sniper rifle.