My favourites are UI Cheats (i use it mostly to get rid of the sad moodlet after a holiday), Whimsoverhaul (more meaningful whims), The Personality Mod (it adds new reward traits related to sims 2 aspirations and it adds whims related to them) and a mod (i can't remember the name) that demands a degree from a certain level in some jobs. Those are my essentials.
I'm thinking about getting Meaningful Stories again. I have had it and deleted it cause i thought was overpowered, but i've just noticed that i can tune it to my liking...