I second: MLO (My life organized) ( a very sophisticated task manager and prioritiser)
Onenote 2007 (especially tagging features)
Outlook 2007 Calendaring and task manager
and some new ones for you all: LifeLog (personal time log)
Sciral Consistency (for regular recurring tasks like tracking food eaten, or exercise)
LifeBalance (similar to MLO above in many respects, though with graphical output for tracking time spent versus where you wanted to spend your time - this is a very nice feature - though overall a smaller feature set compared to MLO)
Achieve Planner Similar to MLO above but with an integrated calendar