We fell in love with Jack and his brother Sam at a pet shop, and although we only really wanted one more kitten we are glad that we went for the two.  They were inseparable during their kittenhood, and still spend a lot of time together. 
Jack and Bluto hate each other, and both have made visits to the vet to be treated, most recently Jack when he had to wear a very fetching 'lampshade' collar.