I don't have a favorite but if you google charity quilts or even free quilt patterns you will come up with tons of ideas.
Here's an easy quilt we just did for our Linus Project. Make 20 blocks of different colorful fabrics each 9" square. Put into two groups of 10 each. Cut Group A lengthwise into two pieces and stich together but for the second piece, take a completely different print from the pile. Now cut these sewn blocks horizontally and stitch, again using different print from the pile. Do the same with the second pile of 10 pieces.
The sashing of 3" will coordinate the entire quilt and what you have is a very interesting child's quilt with many patterns to be discovered.