Arduino Uno R3: $35
Wayne and Layne Video Game Shield: around $30 (with shipping)
Soldering Iron and Solder: I got mine for around $8 at RadioShack
Two way RCA cable
Step 1: Assembling the Video Game Shield
Step 2: Connecting the N64 Controller
Red wire is 3.3V.
Black wire is ground.
White wire is the data line.
(All the lines in the picture above look orange because I soldered jumper wires onto the end of them).
Solder the white wire to the digital pin 2 hole on the video game shield, the red wire to the 3V3 pin, and the black wire to the GND pin.
Step 3: Installing Arduino Libraries and Uploading the Code
If you don't feel like figuring out how to mash all this code together I have provided a completed sketch. Download the files in MacSpinks_Tetris.zip and upload the sketch to your arduino. Then you are good to go! All you have to do now is plug the RCA cables from the arduino to your tv and play.