the one-hand HSPU gets my vote.
I know the triple BW deadlift has already been done, and the 1000lbs squatters probably squat about triple BW (dunno what exacly they weigh, but anyway).
as far as the cross goes, there are more difficult moves - maltese cross, inverted cross victorian cross (has been done only by 1-2 people to my knowledge)
the OH chin also isn’t an uncommon sight, a.l. I’ve seen it done in our climbing gym. I’ve even heard of people jumping up ropes (there’s a video on crossfit.com if you want to check that out)or incline ladders one-handed.
but so far, I’ve only heard theoretical talk about the OHSPU; I know a couple of people who have set that goal, but I don’t know if anyone has ever achieved it. if so, please let me know.
you know what? just continue to work up to all of them…
period.