My favorite pet game was either Pets Society (from Facebook) or Nintendogs for the DS.
I don't have any images of them but I suppose they're google-able. Many hours of the late end of my childhood was spent caring for my nintendog named Tiny, I should probably dig him up from my pile of DS cartridges and give him a bath sometime... Actually, giving your pet baths will definitely be something I'll be adding to my entry.
And then I guess there's "Can Your Pet?" but that's probably taboo in a jam like this!