I voted El Canek, but I would not be mad if Psicosis made it instead. El Canek is clearly the legend here, defeating many greats such as Hogan, Andre, Thesz, Vader, Yokozuna, and also was the first to body slam Andre way before Hogan ever had the chance to. Definitely one of the most over Luchadors to ever exist, right up there with Blue Demon (which by the way I'm still pissed that he didn't get in) and El Santo in popularity. He also had a lot of matches over in Japan for NJPW. As far as Psicosis, man the dude could just go in the ring. If you watch his matches in WCW with Rey Mysterio, they were damn near instant classics from the get go. My favorite was his match against Rey at Bash At the Beach (the one where the NWO first formed). Psicosis just throttled Rey the whole match. He ended up losing, but still put on an impressive performance. His mask was sick, and I loved his Guillotine Leg Drop finisher he used. Either Psicosis or El Canek would be worthwhile as the 5th member.