I have a 5 yr. old (boy) and a 9 yr. old (girl) they each have their own PS3...they both love Minecraft, Littlebigplanet 1,2,and 3...they have the Lego movie game..my daughter likes just dance, we have it on the wii tho...
They both got an innotab thing (if those are the leapfrog thing), but didn't play it much...they always wanted to play my DS, and now my 3DS...my daughter has her own now, and I gave my boy my DS after I got my 3DS...GameStop still has a ton of regular DS games...my daughter really likes the Sims games and My Petz games..they both like pretty much any Mario game, especially Mario 64, and the new super Mario 1 and 2...
I could also suggest an iPad mini..my 5 yr. old has been playing games on there since he was 3-4 and I'm just amazed at the stuff he does on there...he's better than me on a lot of the games we have for it, and he was really into some of the learning games...I do play minecraft with him with my iPad...you can link together on the same world its ok, not as fun as on console or PC...