What features should I look for to choose the most suitable MCU for the TFT display?

I have never used TFT display before and now I need to use it. I found a display which has 800(RGB) x 480 definition. It can be driven with 18 or 24 bit pixel size. So I am looking for the cheapest MCU with or without controller that can handle display. I wont play video, there will be buttons and some other widgets.

This comparison is from ST. I only know I need big amount of RAM(800 * 480 * 3 bytes) if I use display without controller by using bitmap. I dont know what else I need to look for. For example MCU frequency is important for it and what should be the min value? Is it difficult to handle display and other task for MCU if I use display without controller? Should I use it with controller? I can get any advice about MCU or driving TFT display.

Thanks.