I've played thousands of hours of Oblivion over the years. At the very least, I played through all of the content in the game, unlike Skyrim, where I could never bring myself to try the Dragonborn DLC.
Weird to think that in three years, Oblivion will be 20 years old! The leveling system will always be awful, but Oblivion is probably the comfiest game in the series overall. There's not much like exploring the Blackwood on a rainy evening, with the tremendous and atmospheric music accompanying the delve into the darkened swamplands. Maybe exploring the Bitter Coast in Morrowind is a little close.
Didn't Obsidian hired the guy who made OOO?
Yes.