Looking for a guide to best classical recordings

Nick, I use several sources:

Penguin Guide. The "big book" is revised regularly and they also publish a shorter update between printings of the big book.

Gramophone guide. I don't like this as much. They seem to prefer the British orchestras and performers. I'm British, so I shouldn't mind! However, it seems a bit biased.

arkivmusic.com. This is an online store for classical CDs (including many hard to find ones), but they also have interesting and insightful reviews.

I also regularly read BBC Music magazine and Gramophone magazine for new issues.

My point is that you should consult a number of print and on-line sources, as well as friends/colleagues.

The NPR guide gets mentioned, but their coverage is limited and their comments not particularly useful.

Have fun!

the latest penquin guide 2004 has just been released,it includes most all of the new releases thru early 2003.as mentioned in earlier posts,the reviews don't always tell you much about the quality of the recordings,so if this is important to you ,rely on the ones that do.
the gramophone web site is also very informative as they give you their best picks going back 20 yrs. or so.
also the recommendation of the naxos label is very good,especially of the last 5 years of their recordings.the sound quality is right up there with the major labels

Thank you all for the suggestions. I guess by "definitive recording" I mean a combination of performance and recording quality. Actually, I'm not really sure, I just know that there are some recordings and performances that are famous for good reason, and I'm interested in a guide that will clue me in to some of those.

I've got a lot of great leads. Thanks again.

For one man's thorough list, you can check out Arthur Salvatore's "Audio Critique" at http://www.high-endaudio.com/index_ac.html

I have purchased a copy of Muti conducting Mussorgsky's "Pictures From an Exhibition" on Salvatore's recommendation and found the recording to be spectacular in both performance and recording quality.

Nick, I own and use the following guides:
(1) Gramophone Classical Good CD Guide. British. Over 1300 pages. (There is also a shorter version of this book on opera only.)
(2) Penguin Guide to Compact Discs. British. Over 1500 pages.
(3) Classical Music on CD: The Rough Guide. British. About 500 pages. (There is also a shorter version of this book on opera only.)
(4) Jim Svejda, The Record Shelf Guide to Classical CDs. American. About 900 pages.
All of these are fat, large-format paperbacks and all are well worth having and using. Of course they often don't agree, but what is "the best" performance is obviously a subjective judgment. Books like these will certainly alert you to famous, celebrated performances that stand out from the pack. Good luck and good listening.