Pie Heaven

So I'm making various kinds of pie for Thanksgiving and need to enlist help. So far I've got recipes for a great apple pie, mixed berry pie, and pumpkin pie. They are all tried and true. I'm pretty convinced that the pecan pie recipe I have from Martha Stewart is going to be good too, so that's the fourth one.

Pie number five is more problematic. I want to make some kind of chocolate pie, but there are so many and I cannot choose one. Any suggestions? Your favorites, or real crowd-pleasers? Thanks!