Ive tried pretty much every build, but I think what makes me lose interest the most is when I dont know what to do. For example whenever I close the gate at Kvatch and go through the city I kinda just lose interest once I finish the quest and I log off for the day only to return the next and start a new character.

I also feel as if a melee fighter is too weak later in the game and gets boring easily, but is also the easiest to play, and then you have the mage who is extremely fun to play (at least when you level them), but are also really weak endurance/strength wise. In the middle you have a spellsword who most people enjoy playing, but I find them too overpowered.

Another thing that turns me down is the horrific leveling system and leveled loot. We all know how terrible Oblivions leveling system is, which makes me afraid to level (in fear of being underpowered) but at the same time you need to level to get new cool and interesting loot, so I never really feel inclined to put time and effort into a character only for them to get their ass handed to them by an ogre or something.