Reward Traits - which one is your favorite, and why?

Thanks all for sharing your way! :) I'm taking notes and will start buying reward traits for most of my sims who can afford it. Playing 200+ sims, so I'll start with those I played the longest.

But - several referring to the money tree - I used that in TS3 (or TS2?), but can't find it in the rewards list. Are there rewards not getting listed until a certain skill/career level is reached? How do I find the money tree?

Edit: Found it! It was not in the Traits section, naturally :)