I replaced a toilet seat. At Home Depot they had a large selection of various materials - wood, plastic and molded wood. The old one was a molded wood seat that came with the house.
There seemed to be more molded wood models than any other. The paint had worn off the old one in spots and it actually cracked which is what finally prompted me to replace it. I went with a plastic model with a "quiet close" hinge and a quick release feature which seems like a really good idea for convenient, thorough cleaning of the toilet.
I went with plastic because it doesn't have paint to wear off and I'm guessing won't break on the load bearing area like the old molded wood one did and will hold up better over time.
What's the benefit of a molded wood seat? Some of them were pretty expensive, so it doesn't seem to be just a "cheap" alternative.