The biggest quilt I have done so far is a trip around the world quilt. It is about 72 inches square. It was a little difficult to quilt under my machine but, I got it done.
My next challenging quilt will be one that I ordered from connecting threads. It is called "Yuletide Snowflake". It is 82 inches square. Requires applique, still a pretty new thing for me-I don't know how to do it correctly yet-without using steam a seam, and it requires cutting the pieces on a 45 degree angle (i'm nervous about that part-don't want to mess up. But, I love the pattern. I will start it sometime after Christmas.