Of course, the obvious is the wedding ring quilt. I have always wanted to make one, but the idea was daunting. However, I found a really neat way to do it. Here is a link to the demo and templates that are needed. When you see it, you won't believe it.

http://www.kayewoodtv.com

Go to the quilts and wallhangings section and look for the "rings that bind" quilt.