Saki, Goodridge, Overeem & Pat Barry all with varying levels of success.
A lot of females too though it’s hard to say who was really world class because there’s hundreds of kickboxing federations and some are more legit than others. Felice Herrig for example was a champion. Obviously Joanna, Shevchenko & Kowalkiwekcs are all legit.
Not even gonna bother spell checking that lol
There’s also a few point fighting guys.
Edit: Wow I just looked at Goodridge’s record, why did no one stop him from fighting? From 2006 to 2010 he fought like 28 times and won 4.