I came to know a blog of Sara Ford. She has been describing very good and hidden keyboard shortcuts for VS IDE in her blog. Take a look and you will find very very informative (especially if you hate mouse and obviously if you work on VS IDE).
A tip from my side:
CTR + E + C : Mark selected lines as commented
CTR + E + U: Inverse of above for commented lines
CTR + - : Move to next drop mark
CTR + Shft + - : Move to previous drop mark
Shift + F6: To build only selected project (not complete solution)
CTR+W+J OR CTR+ALT+J: For Object Browser