CTRL+K,C - Press both on a particular line or set of lines to comment (them) out.

CTRL+K,U - Pressing this key combination would un-comment the already commented lines.

CTRL+TAB - to move to the next query window

CTRL+SHIFT+TAB - to move to the previous query window

CTRL+M - Display the Actual Execution Plan (Press again to disable)

CTRL+T - Display results as text

CTRL+D - Display in a grid format

CTRL+R - to minimize/maximize the query results window.

CTRL+G - to get to a particular line number

CTRL+F3 - to search and move to the next occurrence of the highlighted item

CTRL+SHIFT+F3 - to move over to the previous matching instance of the highlighted item

F5 / CTRL+E - to Execute again the selected piece of text

CTRL+F5 - to PARSE the selected piece of text. Not Execute, just Parse.

CTRL+U - to go to the database drop down menu

TAB - select a set of lines and press TAB to indent all these line to the right with a TAB space.

SHIFT+TAB - same as above, but the reverse. Indents on the left.

CTRL+SHIFT+U - Transform the selected text to UPPER case

CTRL+SHIFT+L - Transform the selected text to lower case