A couple more shortcuts:

CTRL-SHIFT-SPACE, when inside a function, displays the function parameters tooltip (most of the time ). This is especially handy when Delphi 'forgets' that you want it (e.g. you move the keyboard cursor out of the function for a little while, and then back in).

CTRL-SPACE forces the code insight drop-down list of functions/methods. Again, quite handy.