I think kittens are always better in pairs. It gives them someone to play with and cuddle with, they're more fun to watch, and I've never noticed that they bond less with me because they have each other. My one cat, when he was a kitten, got lonely. I got him to perk up the 9 yo brother and sister I had, but they just wanted to adopt him. He's not a good solitary player, so he seemed a bit depressed. Back to the SPCA I went, got another kitten and they're the best of friends now.