Hmm... With the funny tag, I think I'm going to mostly share non-important ones...
Growing Together
A monopoly-like board game to strain family dynamics and ruin friendships.
Get Together
Special reward traits that do nothing but allow sims to join clubs that have it required.
Seasons
New Year's resolution to pet 10 different animals.
Outdoor Retreat
Forest rabbit hole where sims can get lost in and be away for days.
High School Years
Just add the ability to make custom posts. I want to rant about townie fashion there!
Parenthood
Just put automatic punishments to children making a mess in public.
Horse Ranch
Experimental Nectar that has a random effect. Go on, take your chance.