The best thing you can get is Admiral Kole (+1% to base def and atk) because he will always be useful. You can find him in the Galaxy Pack for 2,5k AP.
Another good thing is the ship White Tiger (3x officer any) in System Pack for 500 AP.
The rest of the items is pretty dated, so after the above mentioned two items, most people just keep buying Planet Packs for 100 AP and hope for the 5x GS you can get there (very low chance).
You may also want to collect Rylattu Engineer and Guerilla from the packs. As far as i know, you arent able to get them from anywhere else, and the amount of different crew helps on quarg proc.
