I was hyped for Oblivion until its release, but was quickly turned off by it. I can't stand, and couldn't then either, it's terrible models, animations, combat, UI, AI, bland world, gps compass, weak writing, etc.You couldn't pay me or bait me with a free copy of Skyrim to speedrun through the MQ of Oblivion, the whole game just has a gross feel to it that I would avoid if given the choice. Skyrim looks like it will mostly be the game that Oblivion should have been, and I'm kind of regarding it as the proper continuation of the series after Morrowind.
What I don't get is how people can complain about how terrible Oblivion is because of models, animations, combat and AI, etc, and then go on to say they loved Morrowind. I can say the same thing about TES: III, but I still enjoy the game.
You don't need to play Oblivion, but I strongly recommend it. People just need to stop expecting one game to be like the next, they restart each TES game from scratch, building them to be a whole new game of their own. Things change, and each game has its pros and cons.
Edit: And while the MQ didn't have the best writing, there was still plenty of great writing throughout other areas of the game.