Just starting out, and so far I've purchased the following:

2 "regular" (not Force Awakens) core sets, an advanced tie, a regular tie, X wing, and Y wing.

I also snagged an advanced tie card upgrade on eBay.

So my question is, what are the first " you gotta get this" ships/cards?

I think I'm leaning Imperials, just because I like the fleet uniformity, although I want a nice selection of ships for scenarios/ campaigns. My primary goal is to get the "right" ships and upgrade cards, without spending a fortune right off the bat. Thanks!