Pandemic expansions

So…a little late to the party but:

Wife and I just started playing Pandemic. We’ve been enjoying it. I started looking through posts on here for anything and everything Pandemic related thinking people would have some discussion of expansions. Turns out, we’re very late to the party and most posts are years old.

So, I ask ye redditors, what say you of pandemic expansion that bring some unique flavor to this game? Recommendations? Any to avoid? Reasons why?

Thanks in advance!