Which pack has been most influential in your game?

Seasons for the weather and holidays (especially since I use holidays to block out summer vacation and I'm really glad I did, it's nice to give my kids/teens a break from school to just have fun with friends for a couple weeks) since it really helps it feel like time is actually passing, and I like that the seasons are different in each world. Parenthood for the enhancement to the overall family interactions and especially the character values. I like being able to influence the values while the sims are still growing up, and then once they age into YA and the values lock in, they really impact the autonomy of the sim. I even go in and cheat the character values for sims that I make who are already past the teen life stage. It especially helps my mean sims actually be mean and cause problems, which is otherwise hard to maintain since sims are always being nice to each other. The life stage phases the kids/teens go through are nice too and help make the gameplay more interesting, and I like that the phases are different between the kids and teens.

2nd tier are Cats and Dogs and Dine Out I suppose. Maybe Get Together as well since I use the club system to help populate large lots, and I make a lot of restaurants and parks that make use of the café bar. 3rd tier is probably City Living, just because I love the world and the festivals are still fun to go to sometimes. I use the city as like a getaway for my teens and YA sims to have a fun night out with friends, and just pretend they take public transport from whatever other town they're visiting from.