Photoshop/GIMP request

If you’re a power user of either of these programs, I would very much like to know what you believe to be the 30 most important application commands, in order of how often you use them. Is it Dodge, Burn, Paste Special, Line, or something to do with Layers? If you are able to tell me the hotkey that triggers the function as well, that would be ideal. Thanks very much.