As of right now, I'm going to have to go with Doughty.
Already has his name on the Cup. There are lots of amazing players through history whose name didn't end up on the Cup. Cup wins are one of the first things people look at, right or wrong, when determining which player had a better career.
When people look back after their careers are over, people won't think about how Pietrangelo brought it night in and night out while Doughty coasted through the regular season (<-- perceived coasting, I dont' watch many Kings regular season games). They will remember how these guys played in the playoffs. And Doughty brings it in the playoffs. I think he should have won the Conn Smythe over Quick personally.
The best thing Pietrangelo has going for him in this poll is his style of play. If Doughty only plays 14 years due to injuries piling up from his play style, and Pietrangelo plays 19, then he might stand a chance.