If you can't beat 'em, cheat 'em.
However, I have to wonder about two things.
First, unless you've actually used all (or at least many) of the boards and services listed, you're really voting for your preferred/favorite/most used board, not the "best".
Second, the methodology seems bad. They give you one vote, but the results are broken into categories -- best free, best commercial and best hosted. This means that the voting should really have three categories so that I could vote up to three times -- once for best free, once for best commercial and once for best service. I may host my board with a service, but also want to vote on boards that I visit.