Depends on exactly what model MacBook Pro you have and what kind of video inputs your TV has.
If yours has a miniDisplayPort video out, then you will need the Apple miniDisplayPort -> DVI adapter plus a DVI -> HDMI cable. Ditto if your MBP only has a Thunderbolt port.
Here is more information about the Apple adapters
If your TV only has composite or s-video inputs (not DVI or HDMI) then unfortunately you're out of luck. At least for any cheap solution.