Oh it's completely random - what I like. Standard playing cards or little card games based on whatever I happen to see and like the art on. Last one I bought was Cat Lady Old Maid. I feel like it suits me, lol. I watch Kickstarter all the time for new ones. They've always got a ton. The deck I take with me camping is Permaculture themed from a Kickstarter done by Permies. I'm all over the place with it. I just like them for the novelty.
Now my stuffed animal collection. That's starting to get out of hand. They might take over soon. Hope they don't ever get the mind to start a mutiny. I'll be facing a mighty fluffle.
I've never ordered any prints. I've seen some beautiful designs I definitely would love to have made, though. But like you said, sucks to spend all that money and have it turn out to be brittle, or just not as nice as you'd hoped. I like your Vitruvian print. Looks nice. That's similar to what I've been thinking to make.
And yeah, I'm already thinking on my next silly post. We'll see what I can come up with.