Last time I had a project on 16x2 LCD display. After that I thought, 'it would be awesome if using a color display instead.' When I searched a color display for Arduino UNO, I found there is limitation using UNO:
"Due to the size of the library I do not recommend using it on ATmega328 (Arduino 2009/Uno) and ATmega32U4 (Arduino Leonardo) as they only have 32KB of flash memory."
The details can be found with this link: http://henningkarlsen.com/electronics/library.php?id=51
To make this project less complicated, I also bought Arduino Mega 2560 finally. : P
This is a 2.4" TFT display with 240x320 resolution that supports both SD card and touch screen. I am so excited and wanna try it as soon as possible.