The North Face: http://prezi.com/-rfna6oubgpo/the-north-face/
Glasses: They are monopolistic competition because some brands may be more expensive than the other because of style/reputation. However, they all serve the same purpose, which is to help you see better.
Call of Duty - Black Ops: Call of Duty can be considered an oligopoly. Reason being that there are other FPS (First person shooter) games for similar prices like Medal of Honor, Halo: Reach, Battlefield Bad Company 2, Fallout: New Vegas, etc.