Shortcut for selecting the first song result from search in iTunes
Assuming the sidebar isn't shown (the current default), in iTunes v 11.3.1, I'm able to:


search (hit enter if you get the popdown results instead of the full window update)
tab 
even though the song
isn't highlighted, I can just hit space and the top song starts
playing.


If you use the arrow keys instead, you can see that the first song gets selected, and then you can navigate the search results from there.

If the sidebar IS shown, everything is the same, but you'll need to hit tab twice.  As an aside, toggle the sidebar with ⌘alts

This is on Mac, on Windows YMMV.