Vintage sets. 57, 58, 67 and 69 are the ones I'm working on and have made great progress. Also, my goal is to own all of Matt Wieters 2009 RC, and I'm getting fairly close on that one too.
Collecting Orioles, Ravens, and Topps Baseball sets 57, (Finally finished 58!), 67, and 69 (need only 2!). Also, MLB HOF Autos.