This is one of my favorite games that's ever been created. What is so great about this game (I'm talking about the PC version, not the console version seeing as I don't own a console and I don't even like consoles.) is that you can download so many mods for it, and use them effectively (OOO mod comes to mind). There are hundreds of mods out there for this game, especially at tesnexus.com. There are mods that change the beginning's tutorial (Alternate Start), and also mods that change the graphics for trees, rocks, grass, NPC's, sound, weather, voices, lighting, your own character and the ground.
In many instances, Oblivion is better than Morrowind when it comes to gameplay. The only part that disappointed me in Oblivion was the leveling system. They changed it from Morrowind. In Morrowind, you had 3 categories: Major, Minor and Misc. In Oblivion, you only had Major and the other category I believe was called Misc, and only Major stats leveled up your character. In Morrowind, Major and Minor both leveled your character, Minor just slightly slower than Major. Everything else, the game didn't disappoint.
In both Oblivion and Morrowind, you could either become good or evil, which did not really change the main quest any. You could gain either Famous points, or Infamous points in the game. You can rob, steal, kill, assassinate, pick locks, buy houses, and complete quests. You can do the same in Morrowind.
I'm scoring the game a solid A