The best packs for you will depend on your personal play style. I suggest checking out the SimsVIP guides and other reviews if you haven't already done so. I also like to build my own bundles and/or wait for sales.
This is how I would rank your options:
1. Cottage Living - I think this EP was made for me. I love the theme, world, activities, and animals. You may want to wait for a sale though unless you really want the bonus items.
2. Parenthood - As a family player, I wouldn't want to play without it. It makes the caregiver-child relationship and interactions feel so much more meaningful.
3. Snowy Escape - It is getting harder for me to choose between them now, but I think Snowy Escape wins. I love the Japanese theme and world, where my sims enjoy fun and relaxing holidays.
4. Get Together - I love the world and the club system is very versatile. I also really like the dancing skill, although I would like it to be developed further.
5. Discover University - I enjoyed this pack much more than I thought I would. I don't take my sims to university very often, but it is great for storytelling. It can be quite challenging, but rewarding to see your sims achieve their dreams.
6. City Living - I am a country girl at heart, but I enjoy the singing skill, festivals, and careers.
7. Tiny Living - I think it's a little unfair to compare a SP with GPs/EPs. It's actually quite a good SP if you like to build and play in small lots. I don't build much, but I really like the CAS/BB items and the perks from living in a tiny home.
If you like supernatural gameplay, I also highly recommend Vampires. It is definitely my favourite pack.
