5. Walder Frey
Who would have ever guessed this scrawny old buzzard to be capable of anything except blathering about his multitudes of plain looking offspring? Walder Frey, Lord of the Crossing, didn't mean much to anyone. Robb Stark sought his aid against the Lannisters, but screwed that one up big time when he went back on his word and married the beautiful Lady Talisa instead of one of Frey's daughters. Besides that little was known about him except that Robb's uncle, the Blackfinn says more than once that he has "seen wet s**t's he liked better than Walder Frey." He really wasn't all that bad and then, well,
it happened. No spoilers of season three will I give here since there seem to be quite a few people out there who don't keep up with the show regularly, but if you haven't seen it yet be ready for a shock. This little old guy lives in two big towers on river hence he is known as the Lord of the Crossing. After what he's done, I hope to see those towers burn to the ground in season four.