Ctrl+Shift+.(Period) to bring up the menu. It is your best friend, and just to list the ones I use most often...
Spawn ships - Change Galaxy -> Spawn Entity
Level up captial ships - Change Galaxy -> Change Entity
Give all planet upgrades - ""
Give all research - Change Galaxy -> Change Player
Show FPS - Overlays
Show entity facts (not called facts, but something like that. Must have for ability modding) - ""
edit: Wiki for a little bit more info. I might have to expand on it.