Favorite? No, don't have one. The ones that get the most wear are

USA Kilts casual Davidson, because it's easy and looks good.
USA Kilts 5 yard wool Davidson, because it looks even better.
Barb Tewksbury Leatherneck box pleat, because I like the tartan and box pleats.
Keltoi Black Stewart box pleat, because sometimes you like a redder tartan color

My new Freedom Kilt Dress Blue box pleat is likely to end up on the short list as well.