He's by far my favorite character on Atlantis.
I think Hewlett does an amazing job with McKay's humor but also shows McKay's softer more vulnerable side. He can do so much with just a look. There's a lot going on beneath the snark.
I'm not an SG-1 watcher so have not seen the McKay episodes. I'll have to do that. I think, however, that McKay has shown a lot of growth since those days.
And he's Canadian!!