Calling all art lovers! It feels like there are new art fairs popping up all over the world, all the time -- and as art lovers ourselves, we think it's great! With so many options out there, though, it's hard to know which ones to splurge on and which to pass up. So here are the five world-renowned art fairs that excite collectors, curators and art enthusiasts the most. In other words, these are the one's you definitely shouldn't pass on if you have the chance to go.