Polk.
The Whigh platform, as usual, involved disagreeable measures such as protectionist tariffs. The Democratic platform was much sounder: it involved an independent treasury and opposed a national bank. Polk's foreign policy was also much better.
Actually, at the time a national bank was a much sounder option than an independent treasury.
This would have been a tough election for me to decide. In hindsight, I would have chosen Polk, as he turned out to be one of the best presidents of the 19th Century. But had I been alive at the time, I would have chosen Henry Clay, simply because I've always admired his politics and what he fought for. He is one of my all-time favorite politicians.