The Force Awakens. They fumbled on Finn's character in the last 2 films.

He should've been the one to use the force honestly. This shouldn't be a thing limited to Skywalkers.

The Force Awakens is probably his best appearance.

You can’t tell me a stormtrooper turned Jedi Knight wouldn’t have been an amazing story! A certain nice change from the usual “kid from a desert planet” story

As with most Sequel characters he was best in The Force Awakens.

He was pretty uninteresting in The Last Jedi (not Boyega's fault for that however). And The Rise Of Skywalker at least tried giving him something...

The Force Awakens because he stood out there the most

I did like his other two appearances as well

The question isn't if you liked Finn, Which I do love him. It's which he was at his best.

All of them but rise of sywalker is perfect