#4 Eddie Guerrero had a hugely popular second run in WWE

Eddie Guerrero made his WWE debut in 2000, and quickly set his sights on Chyna, who he dubbed his "Mamacita". Guerrero had a short reign as WWE Intercontinental Champion after "accidentally" pinning Chyna in a match, leading to a feud between the pair. He often resorted to cheating to win, and then was later caught canoodling with two different women.
Guerrero was also WWE European Champion for a short while in 2001, before being fired from the company due to being arrested for drink-driving.
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Eddie Guerrero then had a brief spell on the independent scene, appearing in Ring of Honor, World Wrestling All-Stars, and New Japan Pro Wrestling, before returning to WWE in 2002. Upon returning, Guerrero won the Intercontinental Championship for a second time.
After losing the title, he engaged in many feuds, including against Big Show. He earned a shot at the WWE Championship after winning a fifteen-man rumble match on SmackDown and defeated Brock Lesnar to win his first-ever world championship in WWE.
Guerrero later teamed up with his long-time friend Rey Mysterio to become a tag team champion. He had many high profile rivalries, most notably against former partner Mysterio, who later dedicated his 2006 Royal Rumble win to Guerrero following his death.