My best so far has been the one I am in currently.
Ground floor business opportunity with nothing but vertical growth potential in a field that has a strong future with realatively minimal competition with a product that is the best in the market (not bragging just fact).

Worst job has to have been working at Round Table Pizza in Sonora Ca. the manager was a total bitch and her husband the pig (asshole cop) would come in and harrass me all the time. granted I was pretty strung out at the time but fuck him and her equally for making my life even more of a living hell than it was.