Which expansion pack can you absolutely NOT live without?

I haven't been all that excited about most of the EPs for S4 - I preordered Seasons (and I have no complaints), but the other two that I own were bought more for content (CL and GTW). I didn't care about apartments, festivals or active careers. The others have things I definitely don't want in my game (I love cats, but I don't want them getting sick or dying, and I was very disturbed by the strays in previous Pets EPs).

There are several game packs, however, that are must-haves: Parenthood and Spa Day, for sure, and the worlds and content for Granite Falls, Jungle Adventures and Strangerville are quite useful.