So I know my own opinion as to the "most promising" alt coin other than Bitcoin, but I'm curious what the popular opinion is for this topic.
I will wait until 50 or so votes before saying which one I believe is the "most promising" and why, so that I can at least see what the unbiased vote result is. I will also announce the "in progress" vote count as I write my viewpoint.
Of course, anybody may post in this thread at any time to try and influence the vote count!

Wow that's great
LTC , as well as PhenixCoin, which is not listed there, PXC has the best most active developers behind their coin right now. Their website, Phenixst.com (free escrow site) Casino, their own exchange coming out soon, PXC was the only coin that successfully got held back off cryptsy to give it more time to grow.
Some people will bash PXC, they just havent studied enough to find whats really important behind a new coin.