I would go with the log cabin myself, because it is quick and easy, especially if you use the pattern from Eleanor Burns, Log Cabin Quilt in a Day. This pattern is really quick to make and like all of her quilts and patterns look good finished too. You might also want to check out The Quilter's Cache and look at all of the patterns there, the square in a square is easy. She has so many beautiful patterns and they are free to download. Gerbie