I like RPG mash-ups but I am not particularly creative with them myself, so I thought I would take a crack at coming up with five mash-ups. To be honest, I am more interested in what other people come up with, but here are some things that have occurred to me:
Constantinople (c. 1150) + Oceans 11 + GURPS: I have actually put some work into this one as my embryonic Onyx campaign. A medieval urban fantasy campaign, featuring a band of specialists engaged in heists against the rich and powerful. It is currently on hold because our Monday Night Gaming Group is busy with other stuff.
Dresden RPG (Fate) + Amish + Jack Reacher: Our in-house gaming group created the characters for this, but the three kids in the group all left for college before we could actually play. My wife created a young Amish woman whose spellcasting abilities put her at odds with her community and her own faith. I was bummed we never played. I was a delivery truck driver with Jack Reacher combat skills (much like real life).
Swords & Wizardry + Realms of Crawling Chaos + Post-Apocalyptic Detroit: It doesn't take much imagination to cast Detroit in this role.
PDQ + Steampunk + Alice in Wonderland: This would take a bit of work and I probably would hack a few existing PDQ-based games but this seems like a trippy rules-lite combo.
Crypts & Things + Weird Adventures + Silk Road (Central Asia): I have always like the part in Raiders of the Lost Ark where Indiana Jones travels to Nepal, plus I am a fan of Central Asia, medieval and modern. I also really like Crypts & Things and Weird Adventures. It would take a bit of work but C&T is really simple and WA is awesomely groovy.
Have you come up with interesting mash-ups and hybrids? Have you seen something created by someone else that strikes you as particularly creative, bizarre and fun to play?