I had a little adventuring side kick, but alas, she dumped me. But, sadly, I'm more used to lead adventurer, rather then sidekick
For me, I'd want more of a Felix Blighter (sp?) sidekick from James Bond. Or Chewbacca, if you will--backs me up in a pinch and is deathly loyal. Loyalty means everythign to me, as does courage. Brave enough to help me out, brave enoug to go with me anywhere, brave enough to be brutally honest and to stick by ones principles. Courage applies to a lot.