Make building a character, be it a Rogue, a Mage, A Warrior, whatever, more Diverse.. To me, Oblivion had the "Im a Warrior/Mage/Rogue/Ultra Dude going on". It just seemed like no matter what you started with, it ended up being the same badass character. You should have to choose a Secondary profession to speciallize in and on top of that, be limited to the skills granted by your Secondary profession. To me, this would add alot more replay value, in trying different Builds.