One of the things that I really think sets Slant apart is the built-in recognition that the most popular option isn’t necessarily best for everyone. The itemized pro’s and con’s give you a quick view of why people like or dislike something, so you can easily say “oh – that very common gripe doesn’t really matter to me, I’ll probably like this one more than the average user.”
Because of this, I think that whatever we pick for a verb, the subject shouldn’t be simply “…the best…” but instead “…among the best…” to explicitly recognize that one size does not fit all.
Okay, on to the actual topic. Do we want the same language for pro/con votes as for options? If so, I’d scratch “recommend” (doesn’t apply to descriptions) and “like” (good for pro but not for con). No problem with “vouch for” semantically, though the extra word might seem inelegant. “Endorse” is pretty solid.
Other suggestions: approve, recognize
alexlifeson approves “Rush” as among the best Canadian math-rock trios.
paulatishin approves “accomplished the mission” as a Pro for George W. Bush.
spiderman recognizes “Electric Company” as among the best childrens’ TV shows.
thewoz recognizes “lost without Steve” as a Con for Apple Computer, Inc.
(Heh, I got spamfiltered for making those actual @references…)