Hello, So i have been using a Arduino UNO for quite a while now and now needed a new board due to some issues ,and am deciding between another UNO or a Mega , My question is that, is the mega compatible with all of the arduino uno shields and Libraries? because i have heard that the coding on the mega differs a bit and that some shields like the adafruit TFT LCD touchscreen is not compatible with the mega. Is that true?
and if it is what is it that differs in the code?, This is something that i was researching for a while now and couldnt find a valid answer for.
Thanks, 
The SPI pins (11, 12, 13) of the Uno don't exist on the Mega as SPI pins; but if a shield has the six-pin female connector that matches the 6-pin male connector on the Mega (near the reset button), that should not matter.
There is more than one Adafruit TFT LCD Touchscreen; you will have to provide a link to Adafruit's product page.
Library wise, properly written ones should be compatible.
Oh okay and my touchscreen isn't from adafruit but still uses the mcufriend library from adafruit ,the touchscreen is from Robotbanao
The shield that you linked states "Robotbanao 2.4 Inch Tft Lcd Display Shield Touch Panel 240x320 for Arduino Uno Mega, Red"
The mcufriend library by David Prentice has conditional compilation for the Mega2560 processor so should not give problems.
Personally I would just buy the Mega and try it. but if in doubt, David Prentice is active on this forum in the displays section; you can ask the question about your TFT and MCU friend compatibility there; just use a title that covers it, not the generic title that you used here.