The games on these websites are non violent (unless noted otherwide) and most are educational in nature. Here students will find games of strategy, logical thinking, basic skills, spatial reasoning, games to improve their hand-eye coordination, and many others.
Arcademics (all sorts of skill buildiing games for all subjects K-6)
Physics Games One of my favorite sites. All games are trial and error with levels of difficulty. One of my favorite ones is "Vampire Physics" - a real scream!
Wolfram (ask any math or science question)