My Dawn OTP is one not on the poll and not mentioned at all in this thread, and that's TotalEclipseshipping, which is Dawn x Darkrai. I got hints from the game, a couple of minor ones in The Rise of Darkrai, then I somehow managed to write a one-shot that convinced me that this ship really isn't terrible. In fact, it's rather beautiful, likewise with the fanart that crops up.
I did vote for SapphirePearlshipping on the poll, because it's a former OTP and I loved the Wallace Cup series of the anime, while I'll always be fond of InfraRedshipping (( Dawn x Mars )) too. That darling was the first Dawn OTP and I'll never forget the thread on here from years ago.