Have you seen Skylanders Spyro's Adventure?
http://www.skylanders.com/I am a tad biased since I worked on it as a level designer and scripter, but it is a pretty awesome game. It's on all the consoles, but the Wii version is the best version. It was the one made by Toys for Bob and the others are ports done by another company.
The game is a pretty simple brawler/adventure game, in a similar style to the Lego Star Wars games. It has a ton of levels, it's multiplayer, and has fun modes like pvp and challenge levels.
So what makes it cool for pet collectors? The portal of power. The game comes with 3 toys, actual little figures, that you put on the portal of power, and that BECOMES the character you are playing in the game. There are 32 total characters, each with their own abilities and upgrades. When you level or upgrade them, it saves the characters progress, TO THE TOY. The toys are completely cross-platform so they work on other consoles.
Here they all are!

Here's the YouTube channel too:
http://www.youtube.com/user/SkylandersG ... ture=watch