The ones we use all day (on a Mac use ⌘ for Ctrl):
VMove tool,TText,LLasso,CCropCtrl+Jduplicates a layer,Ctrl+DdeselectsCtrl+Ggroups,Ctrl+Shift+GungroupsShift+click to select several items, then Space evenly in Properties- Arrow keys nudge 1 pixel,
Shift+arrow 10 Ctrl+0fits the page to the screen,Ctrl+1shows 100%- Hold
Spaceand drag to move around Ctrl+Rshows the rulers/on the home page jumps to search
The full list is in the help center under Keyboard shortcuts. What's your favourite?