After playing Uncharted on my Vita I would compare it to the first UC released on the PS3. It is right up there and it doesn't even utilize the full resolution of the screen. Right now the best looking game in my opinion is Fifa. Take a look at this screen and tell me what you think?
Also the difference is very noticeable on the small screen. Its an OLED screen so the colours, backgrounds and characters just jump out of the screen!