Most incredible show of strength using the force?

I still think the moving of the entire fleet in Jedi Academy was pretty impressive.

Aahhh, but that was a group effort. And concentrated through a nexus.

I would imagine that Palpatine's force storm is the strongest singular use of the force since as far as I can tell things surpassing it usually have the aid of another person in some way.

the fact that the jedi couldnt sense that palpatine was a sith lord until it was too late was pretty impressive , they only had hunches and palpatine played them like a chess board

but its not really strength but still

Luke being able to apparently resist s supernatural black hole is probably the most powerful Force feat in Star Wars.