Not to totally disagree with post #9 ... but I will anyways.
I found chess mentor to be immensely frustrating (they throw you into Nimzowitsch on move 25 and expect you to figure out where he's putting his knights... like, good luck). BUT the price is great and it does help your chess if you work through it deliberately.
Totally worth trying.
totally worth trying, but yeah good luck with the Knights!
love it worth the $
Recomended for beginner such as myself and yes it can be frustrating... to learn the names and move sequences and the rational behind them so quickly. Pricy but worth it.
Unllimited time with a diamond membership.
i am new to chess and have found it to be the best thing since sliced bread 
It's absolutely worth it. You might not predict all the moves the GM played, but whoever's giving the lesson (FM or better) will tell you the problem with a move you make. Even if it's the correct positional idea, there's usually a more precise move that you'll learn. It really is like having a chess coach in many ways, and it covers everything about the game. I think it's the next step after reading instructional chess books to see how your ideas stack with a GM's. In fact it's like having a book giving you a lecture and a challenge at the same time, but you don't have to have a board obviously and it's like that for every subject of the game! You do need a little patience though sometimes, and finding the moves can be tough, but using this for awhile should really boost your rating!
I'm very interested in Chess Mentor. My knowledge of chess is basically limited to the movement of the pieces and my performance reflects that. (ie. The Lil chess Partner routinely throttles me on easy) I have two questions about CM though:
1. Will it help someone as novice as myself?
2. Do you need sound to use it? (My computer has no soundcard)
I'm very interested in Chess Mentor. My knowledge of chess is basically limited to the movement of the pieces and my performance reflects that. (ie. The Lil chess Partner routinely throttles me on easy) I have two questions about CM though:
1. Will it help someone as novice as myself?
2. Do you need sound to use it? (My computer has no soundcard)
1. yes!!
2. no - there is no sound.
I have benefitted greatly from the Chess Mentor. I find it very instructive and enjoyable at the same time. I also enjoy the anecdotes that often accompany the background for the starting positions. As for the price, I have found that the best route is premium membership, since that entitles you to unlimited use of the Chess Mentor, the Tactics Trainer, and lots of other plusses.
Chess mentor is a bargain in comparison to the number of books you need to own to have so many exercises, but it will only be a bargain if you are willing to work through the exercises of course.
For instance do i find the same nice type of strategic puzzles of Silman here than in his Reassess Your Chess Workbook - the only difference is HERE IS EVEN A GREATER COLLECTION OF EXERCISES!
The Chess.com overview page and video at http://www.chess.com/chessmentor/ is much better than that at the product site http://www.chessmentor.com/ but the latter does have a downloadable demo (Windows only) for use off-line.
I found the original http://www.chessmentor.com/ video boring and presumptuous e.g
"...way more than this in the version that you're about to purchase..."
"...don't delay, purchase it now..."
"...dramatic improvement to your chess game..."
i.e. standard, pushy infomercial style but with dull presentation.
BTW if someone say's "greatest" or "best" grandmasters I expect them to be in at least the top 50% of active grand-masters. It would be simpler and adequately impressive to just say GrandMaster (or IM). However, most of the content is by IM's or FM's - the product web-page doesn't name any GM's although we see locally that GM Patrick Wolff is a recent addition.
Hold on, if you buy a year, you get the first month free? I'm confused.
Apologies for gravedigging
I first bought Chessmentor over 12 years ago and updated at least once. The customer service people were always very helpful in assisting and made sure I did not lose my past progress. They spoke on the phone when requested and answered questions. However, after updating a year ago to 3.0, I could only reach someone by e-mail who basically said I was on my own when I could not get the downloaded program to work right. I tried it on three of my computers and the same issue happened. I lost my past progress and can't get it to get off beginners status. I know that customer service is basically a thing of the past with alot of companies but I am still dissappointed that a company that use to have very good customer service has changed to what is now the negative norm; lack of customer service. The program itself is helpful but if you can't get it to work properly or get assistance when you need it, why bother.
YES
it might be expensive compared to a hot dog...
but it's cheap when you consider that you get a whole year of chess mentor for the price of $1 hour with a private GM coach :)
totally agree; I think it's awesome. plus it tracks your previous lessons and you can go back over them at any time. lessons available from beginner to GM. what more could you want?
mmmm....hot dog...drool