One of the beauties of the sabermetric community is the ongoing dialog amongst the vast majority of contributors.  In that context, the community needs forums to have that dialog, and there's no better forum than the various sabermetric blogs/websites in existence.  With that in mind we present the Best Sabermetric Research or Writing Website which was defined as

The best sabermetric blog or website of the year. Define "best" as you wish, though it should be focused on writing and/or research contributions.

Enough babbling by me...  your winners are (drum roll please)....

3.  The Book Blog

Clearly The Book Blog still houses quality research pieces (see for example MGL's aging study); however it's the discussion in the comments that sets The Book Blog apart from other sites.  At some point during the day/week most every heavy hitter (independent of site affiliations) in the sabermetric world makes an appearance in the comments to discuss their work or someone else's.  That makes The Book Blog a great place to go pick up methodological ideas as Tango and the commenters do a wonderful job of highlighting both good and bad methodologies in other studies.

2.  Fangraphs

Fangraphs stable of writers does a great job of providing timely, quick hitting analysis on transactions, recent games, trends in the sabermetric world, and many other topics.  That isn't to say that there isn't significant research going into the articles, just that the authors do a great job of synthesizing all of their information into a concise article that's digestible for even the neophyte saber inclined fan.   

1.  The Hardball Times

The Hardball Times combines quick hitting analysis via their THT Live Blog with longer research pieces in their "front page" articles.  Both of these avenues provide the reader with quality analysis.  To me what sets THT apart is the width and breadth of topics that THT covers to include historical pieces, cutting edge sabermetrics, and even branching out into lighthearted humorous pieces.  In addition to the articles themselves, THT, much like The Book Blog usually contains further thought provoking discussion within the comments.

Congrats to these websites on a job well done!!!

Clearly this was not an exercise to just find the best websites, but to identify a host of good websites.  With that in mind, congrats to the other nominees (listed in alphabetical order)

Baseball Analysts

DRaysBay

Lookout Landing

Sabermetric Research

All 7 of these sites are must adds to your RSS feeds if they aren't already there.