Recommendation for multiplayer (kids will be playing)

Some family members are coming over to my house including two cousins (7 and 12 yrs old). I wanted to hear from you which of these games would be easy to pick up for them and have fun. I have only two controllers:

Metal slug, Excite truck, Elebits,  Sonic (this one is right now unavailable since it is rented)

Well I am going to be renting and those three ( Metal slug, Elebits, excite truck) are the only ones available that I thought would be fun for many people, especially taking into account that some of them are kids.

So I would appreciate the answer being one of those three, since they are my only options:

Personally I am leading towards Excite truck, even though the video store guy keeps insisting what a good game metal slug is (but it isnt even a "real" wii game if you know what I mean)

Thanks for all the recommendations so far