I'd just ignore Oblivion completely, though the expansion content was pretty neat.
I don't think the graphics of Morrowind are really that dated, what I don't like about that game is a lot of the gameplay mechanics. Spellcasting is a nuisance and I always avoided it, and even melee combat could be very frustrating if your weapon skill was anything below 50 or 60. That being said, it probably has the best storyline, the biggest wealth of quests, the best environment, music, and general feel. And dunmer that sounded like dunmer.
Skyrim is also an excellent game, obviously with the newest and nicest graphics of the series, and a lot of the gameplay elements that were annoying in Morrowind have been fixed. I also like the perk system for skills. However, as amazing of a game as Skyrim is, it somehow cant match the haunting and enchanting allure that was Morrowind.
If you could take Morrowind and apply many of the gameplay changes that evolved through Oblivion and Skyrim, now that would be a PERFECT game.