I'm a set collector. The sets that I work on are fairly random, and have a lot to do with whether I like the general look of that year's card.
In addition to the base sets, I like working on parallel and numbered parallel sets.
I gravitate toward these three products:
Topps Flagship Series 1, Series 2, Update (working on 1967, and then primarily 2011 - present)
Topps Chrome: (2016 - present)
Topps Tribute (2013 only, base and numbered parallels)