The shield version plugs directly into an Arduino with no wiring required. The breakout version can be used with every kind of microcontroller.
Both boards have the TFT soldered on (it uses a delicate flex-circuit connector) as well as a ultra-low-dropout 3.3V regulator and a 3/5V level shifter so you can use it with 3.3V or 5V power and logic. These also include a microSD card holder so you can easily load full color bitmaps from a FAT16/FAT32 formatted microSD card. And on the Shield version, we've added a nifty 5-way joystick navigation switch!
You can pick up one of these displays in the Adafruit shop!
1.8" 18-bit color TFT breakout
1.8" 18-bit Color TFT Shield