Lap Desks

I have a 15" laptop and have used a number of lap desks over the years, and none have satisfied me. I don't really need a mouse pad space (trackpad) but it wouldn't hurt to have a mouse space available for gaming. I sit in a very large chair so using the armrests isn't an option. I'm just curious what experience you all have with various lap desks. Any particular favorites? I've seen shelves that you can slide over your chair, to glorified pieces of plywood, but what have you turned up?