Probably some kind of merchant. I'd like to travel around the world, but I'm definitely not cut out for fighting, thieving and generally anything too dangerous. I could just be a super-swish merchant and help out the Thieves' Guild (partly so they don't steal my stuff, partly because I'm just an awesome guy). Politicians seem to run a much higher risk of assassination.
Although, if you think about it, everyone in Tamriel seems to have perfect physiques... So prostitution wouldn't be all that bad.