Sheldon is a nice guy. But he can also be a very demanding friend toward Leonard, as evidenced here.
Added:

The Big Bang Theory Season 5 Episode 15 Quotes

If I had one, mine would be "Brown Dynamite."

Raj

Leonard: Sheldon, Canada is not going to invade California.
Sheldon: Yeah, really? You think those hippies in Washington and Oregon can stop them?