I roll my Sims traits....just to make it more interesting as I'd probably pick the same traits. But the new one that I've been playing with is Lazy....and I love it. I had no idea that lazy Sims left their laundry on the ground....and could fall asleep at the table. My Lazy Sim was out to dinner with the family....wife, kids...everyone is dressed to impress in their formal attire....and my Sim is asleep at the table, in his tuxedo while his daughter is talking to him. I thought this was so hilarious.
I also like the jealous trait. Gloomy is cool too, as I don't like my Sims to always be happy.