If you could pick any 1 game to have a complete next gen HD overhaul..

[Gun Animal]

God Hand. With UE4 quality graphics.

 

[General Twinkletoes]

Bit harsh to warn the guy who mentioned Pokemon Blue, I mean he was being a smartass but it's not like he was saying "HD UPDATE? HOW ABOUT PONG DUFUS!" or something.

It was because of low content, not being a jackass.

OT:
Gonna have to echo OP and say Battlefront 2. It'd getting a bit dated now.

 

[Brodre]

STAR WARS;
Rogue Squadron
KOTOR 1 & 2
Battlefront 2 with BF1 maps included =)

Probably the latter one if I had to choose =)

 

[nexi01]

Jetforce Gemini