8. Rey Mysterio (5'6")
Rey Mysterio is one of the smallest wrestlers in WWE history and also one of the most successful. He's also pretty tough. Think about it. How many wrestlers that are 5'6" 175 pounds have you seen could look credible in American wrestling for nearly 20 years and compete at the highest level? Mysterio showed a lot of toughness for lasting as long as he did. The last few years of his career have been dampened by all the knee surgeries he's had as well as other ailments. The thing is, he had those knee problems well over a decade ago, yet he still wrestled hundreds of matches and will go down in history as one of the most athletic wrestlers there's ever been. What was great about Rey was that he was more than just some high flyer that could do amazing things jumping off the top rope. He was great selling too. He could get his ass kicked as well as anybody and keep coming back for more. Remember Kevin Nash launching him like a lawn dart into the trailer on Nitro? Crazy bump. He was fine after that.
Mysterio wasn't tough because of his submission wrestling skills because that wasn't his style. He was tough because he lasted as long as he did and it's that toughness that was underrated about him.