I my dog because:
She follows me everywhere, and is always right at my feet.
She guards the house when I'm alone.
She cuddles up with me at night when I go to bed.
She has accepted a feline sister wonderfully.
She is always sitting at the door waiting for me when I get home (even though it's partly because I feed her at that time).
And I always get butt waggles when I walk in the door, even if I've just been gone a few minutes.