All of my kids have ds's, PSP's or gameboys (depending on the kid) they are allowed to bring them camping, but only allowed to play in the early morning (when we're making breakfast) or at night before bed, and if it's raining so they don't make me crazy. Rain and a popup with 4 kids and 2 dogs is akin to waterboarding.
We have a tiny television, and it has a dvd player. I bring it, but have yet to use it in 4 years. If one of them was sick and had to stay in, then I'd pull that out.
In the TT we're considering, there is a 26 inch tv, but I don't see myself using it much. They watch too much as it is during the other 3 seasons. My kids would love to bring the xbox, but then they'd never go outside...that would be BAD.
There is a stereo, and THAT I would use all the time. Music makes everything more fun!