Blog Commenting Suggestions

What do you fellow bloggers use for commenting? Do you just stick with whatever your blog place provides or do you use freeware or code? I'm specifically asking because I get questions in my comments and then don't know how to respond to them and make sure that people get my answers. A friend of mine sent me a code that she uses, but I thought I'd see what others are using and if anyone can recommend a good, preferably free, commenting system. I've seen HaloScan a few places, but I'm not sure if it's the way to go.