When my daughter was a newborn, we put all kinds of fancy and patterned sheets on our baby registry. These items were very sweet, and I was happy that my child (who couldn't even see more than a foot in front of her own face) had a nursery that was perfectly coordinated in color and theme.
Now my daughter is a toddler, and I buy what's cheap and does the job.
The patterned, fancier sheets are very cute. However, they shrink and stain just the same way as the plain ol' white ones do and they cost twice as much.
Now I buy the Circo white sheets. They come two to a package for $9.99 where other crib sheets are $6.99 to $9.99 (or more in other stores) for just one. Yes, they shrink to the point where they don't fit anymore. That happens to all crib sheets over time, and that's when it's time to pick up some more. And sure, they wear out. I've never found crib sheets that don't. But these wash well and last for a good long time.
My daughter's room might not be completely as coordinated as it once was, but she's comfortable in her crib.