I second that eye-roll, Naz. With a topic like this, though, I guess it was only a matter of time.
That aside, I’d agree that Smash Brothers is an excellent purchase, especially considering the price since it’s been out so long. Mario Kart: Double Dash could also be good since it has a cooperative aspect to it (it’s a racing game in which both players can occupy the same vehicle, in case you’re curious). However, it’s fairly new, so it’ll still be around full price. Other than that, Super Monkey Ball has some fun multiplayer modes, but the single player can be pretty hardcore.
Also, if the children are male, I’ve noticed that males aged five to thirteen often enjoy games with plenty of guns, violence, and scantily clad busty females. I’m guessing this isn’t the kind of advice you’re after, though.
Damn - I forgot to mention Animal Crossing. That would indeed be a good choice for what you’re after.
Dammit, I also forgot to play it on Christmas Day.
Also, don’t rule out games just because they don’t look as though they’re for kids. Plenty of genres such as racing games may look like adult titles, but are really in no position to contain any violence or adult themes that kids should be kept away from, except for the lowest possible form of violence, such as the occasional unrealistic car crash. Of course, they change the rating from ‘Everyone’ to ‘General’ for a reason, so it’s up to you in the end.