While I have a hapily bonded pair of males, my Little Two Paws lives alone since he is handicapped and might be bullied were he paired with another chin, according to my vet.
He is happy all alone, curling up in his tube, snuggling in his cuddle cup and begging for treats!!! He tends to get extra lovins' from me because he IS alone, and I feel that he needs the extra attention.
One of our little rituals involves me "grooming" him by rubbing my fingers along his nose and eyes, cleaning them like another chin would. He gets that look of pure bliss on his face when I do that and give him scritches, so I know that he's a happy little singleton!!!
Since I tend to anthropomorphize my chins, I'm in the camp of "They should have a buddy with whom to snuggle and interact", but I also believe that with ample attention from you, they can live a happy life as a single chin.
They might even be MORE inclined to be a cuddler...I know that Mr. Whiskers was much closer to me before I got him a friend. He's still very affectionate with me, but he does have The Snuggler and they are inseparable.
Good luck with your decision. Either way is a winner -- you get a chinnie (or two) and he/they get to be spoiled rotten by you!!! :thumbsup: