Ok...I know I shouldn't play a lot of games on the computer but this one is ridiculously fun and addicting! You've gotta try Fantastic Contraption! Description: "An online flash puzzle game where you build whimsical machines to solve each level. Save your contraptions and share them with your friends. Free!"
Questioneering is also very fun. I can rationalize either of these games because you have to really think. Description: "Prove your engineering knowledge in this fast paced trivia game. Challenge friends, choose a team, or just go for the high score."
Oh yeah, if you liked the Fantastic Contraption game, you'll love The Brain Strainer! You get to build a rocket launcher in this one. Description: "Yes, it is rocket science. Can you build a rocket launcher with the GlobalSpec Brain Strainer? The more objects hit by the ball, the more points you score--and make sure that you hit that button. Be sure to blast your rocket within the 10-minute launch window or you will no longer receive points or qualify for the high scoreboard. Select a difficulty setting, start building, and fire up your imagination." This site also has Design a Parachute and Power Up and links to many other games.
If you want a link to a lot of engineering games, try engineering.com. Description: "The ENGINEERING.com games and puzzle section offers challenging games and puzzles for engineers. Whether you're a Mechanical Engineer, Chemical Engineer, Civil Engineer, Automotive Engineer, Electrical Engineer or Mining Engineer there is an engineering game, puzzle or quiz for you."
If you'd like to get your kids involved in some thinking games, try iKnowthat.com. Adults will enjoy these games too.
Edheads is also a terrific sign for both the young and old. It has Shockwave learning games on the subjects of Weather, Simple Machines, and Virtual Knee Surgery.
Rollercoaster Creator is also extremely fun and addicting. Description: "Build your own rollercoaster and collect all the coins in the game. Earn thrill coins by making your track more sensational!"
This is some silly fun...Browser Ball. This is the description from the website: "Browser Ball attempts, with only moderate success, to allow the configuration of a seemingly endless array of continuous spaces using multiple overlapping browser windows. Within this multivariate space, users are invited to toss a beach ball both hither and yon. If this sounds like a ridiculous use of everyone's time, that's only because it is."
I love The Eyeballing Game. Description: "This game tests how well you can visually estimate things like equally bisecting an angle, finding the center of a circle or triangle, finding an intersecting point of three lines, or completing a parallelogram accurately. "