WordPress comments and Facebook comments

I’ve used these two plugins:

1) Disqus Commenting Plugin – the easiest way to add facebook functionality to your wordpress blog:

They allow a whole host of features including facebook, twitter, google login/commenting and some other cool stuff. It will probably be more than you need but you might like the extras and the easy setup.

2) Simple Facebook Connect Plugin:

This one is more targeted to facebook and allows a more piecemeal approach to adding functionality but is harder to integrate with your theme and setup.