I've used the Palomar knot for everything...except line to line of course...and it has never failed me. Mono, Floro, Braid, 4lb mono to 65lb Braid and everything in between. It's just the easiest for me to tie and it's plenty strong enough. I've never used any other knot enough to get really efficient at tying them so that's a factor as well...Me and that clinch knot do not get along at all!!!
If I'm using a swivel to connect a leader I even use a Palomar to conect the leader to the swivel first then use a palomar to attach the whole rig to the main line.
