I used to use only the 'nice' traits before but recently I've been using the CAS Create-A-Story feature which has nudged me to use different traits and it's really fun. Hot-Headed, Jealous, Evil and Hates Children are four I never used to use; now I have several sims in my current game with these traits and it's added so much diversity to my game. I'm also using Non-Committal and Squeamish, neither of which I've used before. It's been great to have the diversity in my towns! <3