I had a level 37 stealth assassin, then my PS3 died, so I created another stealth assassin to level 15, then decided to try out a battlemage. Got the battlemage to level 19, and decided he was too weak, and for some reason I need to use a shield (getting hit by a sword without a shield to me means instant death, I need to at least feel like I can justify all the weapon swings that I'm taking). So now I'm up to level 23 on a new stealth macer.
Each restart I kept the gameplay fresh by doing a different path: imperial, stormcloak, striking out in a different direction then I did with other characters, thieves guild, dark brotherhood, etc. The only similarity so far between all the characters is that they all live in Whiterun