I agree it's always good to get a pair of cats, littermates are a particularly good choice.
I myself couldn't persuade my husband of that, he's a dog-lover exclusively, so we just have one. He's an indoor cat, so he does get lonely. I'm still working on softening David up, but since we're downsizing to a condo in a couple of years, I think a second cat is probably not in the cards.
I admit I prefer males, but if I had a pair, I would have one of each.
