I've never played Crazy Kong, but I did killscreen Monkey Donkey on my first attempt (to spite Brian, who was bragging a ton about Killscreening it) without knowing anything too specific about the game before hand. KS'd on my 2nd man; and the only reason I lost a man was because I used it to test if something was the case on the first conveyor stage (If I recall correctly). So, knowing I had DK skills going into it, I think it's clear that certain versions of DK a lot easier to KS, but going for max points is a whole other story. CK may be easier to KS, but games can always be pushed to a level where they become hard. It's only the games where even the best strategies are just mindless repetition (or something of that nature) where I'd say they are "easy" games.
Like BurgerTime. I would say BurgerTime is a very easy game, even at top play.