4. Chris Jericho
In 1996, Scott Hall and Kevin Nash jumped to WCW from WWF, and while they had to leave their names and theme music behind, they more or less retained the same basic gimmicks they'd had throughout their tenures up north (much to WWF's chagrin). In 1999, WWF showed that two could play that game when Chris Jericho made his debut in a promo with The Rock. Save for an "H" that was missing early on, Jericho had the same name since his very first match. After joining WCW, he took on the nickname of "The Lionheart," which was possibly a throwback to his stint as "Lion Do" in Japan, and was played up as a courageous cruiserweight good guy. That is, until he turned heel; that move would seem to inform Jericho's gimmick from then forward, as his promos were more snarky, sarcastic, and at times, even comedic (look up "The Man of 1,004 Holds" sometime). Jericho debuted in WWF towards the end of 1999, and while most lion-themed references were now replaced by "millennium" names and themes, little of it affected his actual gimmick, right down to switching "WCW Monday Jericho" with "Raw is Jericho."