I had two of these sheets for my first child because that's all I could find at the time. Other reviewers are right on about the quality. VERY thin and not very soft either. You can see the pattern right through them.
Now that we're expecting our second child any day and she'll be sleeping in the play yard for a long bit, I wanted to see what else was out there.
I found the following brands at BRU, bought one of each and tried them on the bed. Here's what I found:
Nojo: Terrycloth-like fabric. Soft but still a bit thin. They are elasticized though, which is easier to put on and stays on better. There were three colors available at the store (dark blue, light blue, white). Price $9.99
Graco quilted sheet: Very plush, though the fabric is synthetic feeling (I didn't check, but I'd guess poly blend). Most comfortable of any that I tried. Will probably use it under a more natural feeling sheet. Elasticized and stayed on well. Was only available...