I enjoy them all, but of those listed I’d choose AMB. It has so much content and I use many items from this pack in every single save. I don’t think there was anything from this EP I didn’t like.
I love self-employed careers and being able to consign goods such as sculptures with the sculpting skill. The hands-on professions like firefighter are fun alternatives to self-employment or typical RH careers. Being an inventor—creating widgets, toys, miners, time travel machines and Simbots as well as being able to blow up stuff around town—is also fun, lol. I also love the swampy bayou vibe of the Twinbrook world.
If those things don’t appeal to you as much, SN would be another solid pick. It’s also packed with a great deal of content, fun gameplay and comes with a very nice world in addition to the various occult types.
GEN helps flesh out the life stages, but feels much lighter in comparison and didn’t come with a new world. The content it offers is nice to have though, especially if you play multi-generational families.
ST is also a nice EP and comes with a new world, but you may get less use out of it overall in comparison to some of the other packs because of its heavy focus on the performance careers. However, things like pool tables and photo booths are a few of the objects that are nice to have from this one.
Congrats on doing so well with your exams and have fun with whichever EP you decide on! (And maybe you did well enough to reward yourself with more than one? ;) )