We were also hardcore gamers/sadists. We beat those games because we didn't know any better. This is a pretty casual little girl we're talking about here. If she was more of a gamer, I would opt for something a little more difficult and with a story. 

Anything that burns energy. (RRR, M&S, WW: SM)
10-year-olds always have so much energy, like they drank an energy drink.

 i enjoyed your past 2 editorials, so meh.

and my votes on either brawl or No More Heroes, depending on how violent she is. and from your description of "kicking the living shit out of everything in sight" (or something of the sort) i would more reccomend the latter, assuming her parents do not mind excessive blood + cursing. otherwise stick to brawl, or at the very least metroid prime or wario ware. 

No more heroes is epic...

Hmmm, from what it sounds like Brawl, or Party games would be good for her (Maybe even something like WarioWare, that's a bunch of fun) 

I play brawl with a Wiimote/nunchuk. I think it's more fun that way, I can't do just wiimote alone, haven't tried classic^^; and gamecube controller just feels too... melee >.> so yeah. I dunno, I'd say get Brawl and get it over with :3 if she likes fighting stuff then that'd probably be just right^^ it's a riot of a game anyway.

I see no reason to not get Brawl. Lots of stuff to do single player, kick-ass multi-player, tons of little things to fiddle with and collect, and easy to pick up and play. Plus she enjoyed Melee. I hope she still has her GC controllers. If she does, you're set.

I haven't tried Wiimote/nunchuck with Brawl yet, but I've read it works perfectly well. The only thing would be having to adjust to the differences if you've got Melee with a GC controller burned into your circuits.

I concur on Galaxy being easier than Sunshine.

Invent some excuse and wait for Wii Fit :D

Endless Ocean, the younger girls in my family love this game, particularly their dolphin buddy, and exploration, very easy to use as well

I have a 9YO girl that likes violent games as well. She played endless ocean and animal crossing (DS and GC) a LOT. She also really likes some of the more violent games out on the 360 and Wii.

One game instantly comes to mind that we ALL play. Mario Kart. If you HAVE to buy a game right now, buy the complete star wars trilogy. It is remarkably fun for an adult and a kid and has a LOT of content.

My daughter also enjoyed the heck out of Twilight Princess and it does provide a significant experience as well.

OK.. brawl - she will not get much out of it if she is 10 (and found Sunshine difficult last year) because it is a pretty difficult game to learn and get used to, and to be honest, i think it is geared slightly more towards boys, despite my relos (some of which being girls) loving it.. but a 10yr old girl might not get the same pleasure from getting beaten to death on easy mode

SMG - the games first 60 stars are easy enough, sunshine was a complicated game, that usually required near perfect movements which is probably why you had to play through the whole game with her... SMG is not the same, the difficulty builds up slowly while also having fun games like manta racing which she can enjoy herself

Zack and Wiki - only commenting on this because a few people mentioned it.. No.. just no.. not for a 10 year old. EDIT:masschamber makes a good point in that younger people may find it easier to solve certain problems than older people

RRR1 - these are pretty fun minigame collections, which i believe are worth their value, however, they are more fun when played with others, so if she doesn't have a brother/sister/cousin to consistently play with, you'll find yourself playing this with her too

Super Paper Mario - maybe..... well it has an easy to follow story.. but its main problem would be too much story (text) and if she doesn't like that then stay away, the 2d -> 3d thing may be hard for her too, not sure

Endless Ocean - its a nice game, if she doesn't care too much about high scores, beating friends, finishing the game, then this is a good pickup for just some fun swimming

MySims - haven't played this one myself, but i was interested in it for quite a while.. if she likes previous sim games, this might be a good pickup for her, has a more fun approach to the sims

Mario Kart - if she can hold out for it

Anyone else find it extremely funny how after 3 pages, we are still struggling to find a 10 year old girl a suitable game for the "kiddy" console?

If she is a pretty casual little girl I will recommend Warioware...
If she is a pretty funky little girl I will recommend RRR 1 not 2....
If she is a pretty naive little girl I will recommend Cooking Mama...

Actually Wii Sports is enough for little girl.........like my girlfriend, she still can stick for it everyday.