Hard to say, but at the moment, 5.9m simmer icon, its the sail size I use most often and the sail is super stable in the gusty crap that we often have to sail in.
got a fair bit of new stuff, and gear coming that i've yet to have a good session on, so may change. I think I will have my perfect quiver soon

99L freestyle board, 84L twinfin wave, 75L singlefin wave... and 5.9+5.3+4.5, from subplaning to 30kts, qld conditions covered