Ace Combat 4, 5, and Zero. With Ace Combat 7 coming out I am hoping they put the golden trilogy on PSN in HD via the PS4's PS2 emulation or on PC. They already ran in 60FPS on PS2, just need HD. Also AC6 wouldn't hurt
Panzer Dragoon. I have only ever played this on PC, I heard that Sega has lost the source code and a digital release may never happen though. The game is also a full unlockable in Panzer Dragoon Orta, so maybe port that too.
Mercenaries Playground Of Destruction. PC or newer console port would be fantastic. Also maybe add a radio for driving...
Sudden Strike series.