MacRumors Forum

Keep up to date with the latest Mac rumors, updates, and happenings.  Also includes some nice Mac support forums. 

IUseThis - OSX Software

A nice place to keep track of what software you use, see what others use (free and non-free), and rate your favorite apps.

MacTips.org

MacTips has a lot of good tips for your Mac.

MacWorld

A great information source of all-things-Apple.

Apple Insider

Lots of Mac news, information, and rumors.

Mac-Forums

Another good Mac support/discussion forum.

Mac OSX Hints

Another good Mac support/discussion forum.

MacNN Forums

MacNN is another good Mac discussion forum.