I generally don't buy third-party products, but there were a few things I liked back during the 3.5 days. I was rather fond of Arcanis and Kingdoms of Kalamar. I never played either of those outside of organized play though, and those experiences were limited. I also purchased World's Largest Dungeon by AEG, but that was only because it was a steal ($10 on a clearance rack). In the early days of 3e I also bought some of AEG's adventure modules, but I found them to be terrible in general when compared to "official" adventure modules. I think the third party stuff I was most intrigued by was Monte Cook's Arcana Unearthed and Arcana Evolved. Those really sparked my imagination. I also bought the Ravenloft licensed material because, well, Ravenloft.
As for recently, no, I haven't bought any third-party products because I haven't been playing PF or 4e. I've been sticking with 3.5 for the most part. I have all the books and I like the system so I see no need to change. My tabletop group has finally convinced me to try PF for our next campaign though, so we'll see what happens.