Several people (well, one) asked for the templates for my web feeds, particularly the one that provides comments interspersed with the entries. This will only help you if you work in Movable Type.
My template for Atom with Comments is the only one of interest. It is based on the Atom format and contains the latest blog entries plus a separate set of the latest comments. Most feeds that offer both the blog entry and comments embed the comments into the web feed entry for the blog post. I think this method is better because my readers have the opportunity to see comments on old entries, and they do not get the original post repeated every time there is a new comment. For this to work well comments must be moderated on your blog, otherwise you run the risk of dumping spam into your web feed and into the aggregators of all your wonderful readers. Bad karma! MT makes it easy to do this.
For other types of feeds, check the baseline feeds for Movable Type in their default templates page. I have modified my default templates a bit, based on suggestions from around the web. Learning Movable Type is a great place to start with these changes.