Slow Pitch,
I don't really have a favorite but gleen something from all the free ones out there. I just refuse to pay for any site...though I have been giving serious consideration to paying for a Baseball HQ subscription. Anyway, here our some sites I like with their rankings:
http://games.espn.go.com/frontpage/flbdraftkit Their draft kit was posted this weekend
http://www.rotoauthority.com/2008/02/free-2008-fanta.html Tim Dierkes has offered his spreadsheet for free with rankings, $ values, and projections ...really good stuff here
http://www.fantasygameday.net/ Kelly is the author of this site and while he does not have a nicely packaged draft kit, you can find his rankings throughout the site
http://mvn.com/mlb-fantasy/ Thes guys run a great and informative site. They do not mindlessly follow lock step with the other experts. They actually provide some good analysis as well. Their draft kit is not ready yet, but they have begun to release it piecemeal.
http://www.melnickandgrecofantasysports.com/ This Lenny Melnick's new site with Paul Greco. There is a draft kit on the site, but I believe it is all Paul Greco's work. Lenny has rankings and such, but it is all through his podcasts...not written. Not a big fan of Paul's work, but I admit I have not looked at it yet this year, so it may be improved from last year.
And of course you can go to CBS to see their rankings, but if they are anything like last year, their rankings stink.
Hope that helps!