Knoxville had the most balls when it comes to outright dangerous shit, every stunt he's part of is entertaining in the "he could become deformed, maimed, or dead by the end of this" way.
Pontius has a really fun personality and he rarely ever bitches about doing stunts or bodily harm.
Steve-O is a master at athletic stunts and gross shit, he also seems like a fun dude in general.
Ryan Dunn would do stunts that wouldn't work outright and he wouldn't bitch at all, he had a ton of balls and was the only member of CKY to not be self destructive when it comes to lifestyle choices (minus the car crash that killed him :'().
Bam Margera is a fucking baby.
Wee-man is cool.
Preston is another baby.
Danger Ehren seemed like a try hard for attention.