I'm annoyed that we are getting fewer dungeons this time around. With the fun I had with Oblivion's four dungeon types(Aylied Ruin, Reman-era Fort, Mine, Cave), all done by one person, I'd expect 8 people working with even more dungeon types to make them even more enjoyable.
I never got bored of the Aylied Ruins or Reman Empire Forts of Oblivion, despite the repetitive architecture and tilesets. Where others see monotony, I see consistency. They were tied together thematically, and the amount of literature in-game about them was really
Actually, I never had
any problems with the Ayleid ruins at all. The Varla and Welkynd stones helped: Though I never used them because they weren't renewable, they were shiny, unique, and fun to collect: Great trophys. The sheer size of them, and the amount of in-game literature and quests involving them kept them unique and fun, even if the loot was rather predictable.
And, there were always slight differences between the dungeons in
Oblivion, and the similarities made those differences stand out, and the entire dungeon more fun than had they all been completely different.
Outside encounters, I find, are usually annoying at best. Mostly because of the foes being pointless "wandering Monsters". When I fight, I expect loot. The outdoor encounters always had boring loot.