I got so relaxed I felt hypnotized. The only really annoying part is they make you stay in bed for the duration of the stay. I longed for a hike, or any kind of exercise. They do it both for safety, and so you stay on camera.
Yes, take games, books, etc. You may want to call in advance and ask if they have free wireless internet, webtv, movies, etc. It helps to know what you'll already have there. I stayed at a public hospital that was like a cruise ship: movies, online games, webtv and free wireless, cell phone usage allowed, music on demand, 24 hour ala carte menu-driven room service with fabulous food. I'd go back any day.
There were two things I wished I had brought: a power strip and a container of oil. I know, it sounds strange.
The only place they would let me plug in my laptop and cellphone and charge them was out in the bathroom, to decrease interference with the monitoring leads. There was only one power outlet in the bathroom. Impossible to charge both over night. Power strip would have solved that.
The oil is to get that darn glue off your head afterwards. Take along about a half cup of any kind of oil. Work it into your scalp, using your fingers to work it into the glue. It can take about half an hour of working the glue between the ends of your fingers before it dissolves. Then shampoo. Then do it again. After you dry it you may have something that looks like really bad dandruff. That's the glue you missed, so you may need to do it again. I did it at the hospital because I didn't want to clean the oil out of my shower at home. Let the hospital staff do it.
Good luck!