The ones I sail, because it's obviously the best, and everything else sucks.
Alternative answer for sponsored sailers / shop owners "The ones I'm paid to sail, because I'm paid to spruik them, no really thou they are the best (no sarcasm)"
the best second hand deals I can get, (I buy off sponsored pros) and mostly the sails that fit on my masts....
Boards that ideally come with foot pads, foot straps, a mast track and somewhere to put a fin underneath are a winner with me.
Pesky vent screw optional!
I think most riders get so used to the feel of a brand. When they jump on something else it feels weird and don't think it is as good as the one they already have.
The big thing that influences my choice is reliability. I don't want unnecessary breakages.
and na no sponsorship from either 
i bought the gear i have purely on the looks now that i have riden and gotten usto it id buy more of it beause of the looks and the feel
Does it have to be what I ride, or can it be what I'd like to ride?
What I'd like to ride:
2012 iSonic 107 - reason - everyone that has bought one has gone from being slower than me to being faster than me. :-(
What I currently ride:
2007 Exocet Warp Slalom 67 - reason I like - very comfortable ride, easy jibes and up until this year competitively fast, but not any more. :-(
and na no sponsorship from either 
