What are the biggest differences between the Medal of Honor games and the Call of Duty games? Which is better?

I loved Modern Warfare 2 and im for sure getting the new call of duty when it comes out. How do the Medal of Honor games compare with the Call of Duty games?What are the biggest differences between the Medal of Honor games and the Call of Duty games? Which is better?
I would say call of duty games are better having played both types not reely much differences but if you had to choose

COD every time