I have a queen-size set of Pure Beech Jersey Knit Sheets, and they are incredibly comfortable.  I used to own a twin mattress, and first bought the sheets for that bed--only 20 bucks for the twin size!  My previous set wore a little thin in spots, but it took about 2 years to get to that point, and I use my bed as an office desk (more wear and tear).

The queen set is holding up fantastically, and more importantly--there really are no words for how comfortable these sheets are.  I have no interest in buying sateen egyptian 800-thread count whatever, because no bedding I've ever slept on has been...