It varies. It depends on what I can afford any given week, and how much I want something. I collect 2600, Intellivision, C64, NES, SMS, Super NES, Genesis, N64, GCN, Wii/U, GB, GBA, DS/2DS, and PC games.
But I also don't buy any, and everything for them. I just get stuff I know I'll fire up. I don't shoot for ultra rare stuff because it's expensive, and usually isn't very good. Case in point That Flintstones platformer on the NES
everyone loses their crap over. But there are a handful of ultra rares I would pick up if I could afford them.
I also tend to like a lot of under the radar stuff. Great games not a lot of folks have heard of or played. My last trip to Retro Games Plus was fruitful. I found Sorcerer, Roc'n Rope, and Sub Scan along with a Man-E-Faces
action figure fairly inexpensively.