I was going to suggest a rail fence also....looks like Jeanne beat me to it! That is a quick quilt to make. A Square within a Square 2 would work too. Let me see if I can find a picture of that one. Here's the block pattern for that. It is also quick to make...not that you asked for that.
http://www.quilterscache.com/S/Squar...res2Block.html
Dina