I like Hug, but he was taken too soon to be considered for the top all time ranking. For this, I'd rank it Aerts, Hoost, Semmy, and Remy, in that order. Schilt's got the potential to be 1st if he keeps dominating.
I expect Schilt to surpass all K-1 fighters in acheivement! Semmy is just is not losing any fights, no one can beat Schilt right now. Semmy is probably going to win his 4th K-1 World Grand Prix in a row this year and set the record.