Music Lover, Cheerful, Bookworm and perhaps a few others that has no negatives.
The ones with negative moods, seems really harsh, tried a foodie, neat cook once, but oh my, he was very unhappy, either because the food was bad or something wasn't clean enough.
Insane has a downside, since talk to self is a secondary concurrent item and it is something the sim will queue autonomously a lot, it can really slow down whatever main activity you want them to do (They eat slowly because of it). Even creating a nice looking desk with a computer has this problem, since the sim will use the computer and then also look at all the nice art items, slowing down the computer use, add Insane and they will look at art, talk to self autonomously, while your trying to get them to read a web site to make them focused.