I currently use the cheap contoured cupped kinds (I think Bucky, currently), which are adequate. I find the cups vastly preferable to having something pressed against my eyes, and I dislike masks that feel heavy. A cheap mask will keep out most light (but not all of it). For the most part, they work. Sleeping with a mask is better than sleeping without one.
The problem with the cheap brands is that they always inevitably fall apart 3-5 months after being purchased, especially if you wash them. They're almost all glued, not stitched. They use materials like velcro everywhere.
A while back I tried to do some research to see if there was a premium market for nice, really durable, stitched brands. I couldn't find anything that stood out, it was a big surprise. I've considered trying to find someone on Etsy to try and custom make something.
Right now I'm paying $10-16 every 4 months for a disposal mask. I'd happily pay a ton more for a lightweight, cupped mask that actually blocked 100% of the light and that would last me a few years.