Anderson Silva, Nathan Marquardt, Mike Swick, Dean Lister, Chris Leben, Trevor Prangley, and if UFC gets crazy and throws hella loot out there again maybe Frank Shamrock. That's a big maybe though. If he takes on all those challengers, you gotta think one of them will get it done. Anderson Silva and Dean Lister have the best chances, as Anderson can end it quickly with a knockout, and Dean can end it quickly with a submission. They're among the best, especially at 185 in the UFC, at what they do. I don't see Swick or Leben being on Franklin's level, and Marquardt hasn't looked as good in UFC as I expected him to so I don't want to jump the gun saying I think he'd be a good fight for Franklin (even though, well..I do think he would be). Prangley is a bit of a question mark still, he's shown glimpses of being a really bad ass 185'er but seems to fall short a lot.