I have Apple's and Roku's in the house, but for best bang for the buck the Roku is the choice. You get Netflix, Amazon, Crackle, etc. on the Roku and really only Netflix on the ATV. The Apple interface is way better than the Roku and looks much classier. Both are tiny devices and easy to stash out of the way.

As far as connections the ATV is HDMI only, but the ROKU can be hooked up via composite.

HTH

edit: To hook your MBP to your TV you will need to get a mini-display - HDMI adapter