I noticed that kids don't care at all about graphics unless they've already been spoiled by modern graphics.
As I mentioned, my best friend is raising his kids on a diet of Atari 2600, C64 and Amiga games and they love that stuff.
So for kids who don't care about modern AAA graphics, you can't go wrong with the time-defying classics from the GOG catalog:
-
Super Frog -
Hocus Pocus -
Gex If graphics do matter to them, then Rayman Origins is where it's at, as Leroux has already mentioned.
And then there's all that more recent platformer/puzzle stuff which I'm sure has an appeal to most kids, here are some that haven't been recommended yet:
-
-Mousecraft -
Teslagrad -
Gateways -
Clarc -
Tales from Space: Mutant Blobs Attack -
Ethan: Meteor Hunter -
Chronology If your kids like puzzles more than platforming, here's a personal secret gem recommendation plus it's entirely for free:
Nanobots by Erin Robinson:
http://livelyivy.com/?page_id=73 This is a short, very cute an surprisingly clever point & click adventure game focusing on solving puzzles with a team of little robots, each of which has a special ability. This game requires lateral thinking and team coordination, I fully approve of this even for grown-ups!
HiPhish: I agree about Stronghold and the managerial games, but then again some children are pretty intelligent for their age. The reason I mentioned those games is that they are not as abstract as other games: in Stronghold you have your little villagers walking around and working and every step in the production chain makes sense, like growing wheat, making it into flour and finally baking bread out of it.
But as I said, the best thing would be to just get them a Nintendo, Sega or, as you mentioned, an Atari. Those games are fun, easy to play and well-suited for children.
Truly some kids are surprisingly smart, now that I think about it Stronghold is one of the easier RTS games to learn.
I completely forgot that you can turn down the difficulty to easy which would make the game a cakewalk and suitable even for novice players.
There are a couple unbalanced difficulty spikes in the game but that only applies to higher difficulties. There are two siege missions in the campaign that are tough as nails on the higher difficulties. Talking about the current patched version, not the old version where you could do tricks like shooting from a blind spot behind some rocks without getting hit yourself.
And then there's the economic mission number 7 called 'The Wolves' (not to be confused with an earlier, easier mission which also features wolves). This is the single hardest mission of anything in Stronghold & Stronghold Crusader. If any 7-year old can pull that off on anything higher then normal difficulty, I'll be seriously puzzled. In general, kids like challenges but don't seem to like excruciatingly punishing difficulty.