What sites, blogs, etc have you found instrumental in researching openings.

The purpose of this forum is to save players a considerable amount of time in scouring the internet in an attempt to research an opening so please feel 0free to post your favourite links.

If you don't have CB, I'd recommend http://www.shredderchess.com/online-chess/online-databases/opening-database.html

as a good database - the reason is that the database is compiled ONLY from GM games.  

Thanks

Chessopenings.com

What's the best source for annotated games in a particular opening/ defence that has a wide database per opening?

I have found that the games database at chesstempo.com/game-database.html to be extremely flexible and robust. You can quickly analyze many variations and use any part of the games database for analysis (e.g. GM, > 2400, etc.) I haven't found a better tool on the Net. I use it conjunction with Houdini for analysis of different lines. 

That keeps coming up consistantly.