The 7 inch tablet is used more in my home than the 10... I think it's more comfortable to use to read on, and annoyingly, my daughter seems to think it's easier to game on than the 10. In my experience gaming on it, I'd mostly agree... Touch controls need to cover too much space on a 10.
Movies are an area where the 10 may be better than a 7 though. When you're going to watch a movie, a big screen is more important than ergonomics!
So, overall, I vote for the 7s.