Originally posted by dot-dot-dot
Whichever you're more comfortable with.
Normally, a right handed guitarist would sit most guitars on their right leg when sitting. That makes it easier to reach the end of the neck, and is probably closer to the position the guitar would be in when playing standing up with a strap.
its true that most sit on their right leg, but as others said, it does not help you reach the end of the neck. thats what the left leg is for.