In my large BOB I have a Green Eureka K-2 XT that has been excellent. After 3 years it's still in great shape. I use a Eureka Floor saver with it.

In my small BOB I have a 10' x 10' Polyurethane Coated Nylon Tarp, which I'm really starting to use over the Eureka because of the ease of use and versatility. I'm thinking about adding a mosquito net to this setup.