1. Ascent - don't even think about it, best $35 or so you will spend! It is fantastic. I've been using it for years.
2. TrainingPeaks.com: This year I decided to keep track of all my other workouts (mostly climbing and yoga) plus weight, sleep, stress, etc. TrainingPeaks allows you to easily download the cycling stuff, and add other workouts, etc. I don't like the way it handles cycling as much as Ascent, but it is giving me a very good overview of my whole fitness profile. Web-based (Firefox)
PC, running PC Coach (no Mac version) and a Polar 725i, uploading to PC Coach and to the Polar ProTrainer software. I haven't tried any of Polar's training plans, using the PC Coach plan for general structure. I like the 725i because it's a wrist instrument, so it works for everything. They have a newer and better one now.
Garmin Training Center for general statistics. I import the data into PowerAgent if I want to do more in-depth analysis. I've been thinking about trying SportTracks this year.
FitDay.com (free) is a good site to track weight, body measurements, mode, calories, etc. It stores your data longer than Livestrong and lets you create custom foods. It gives you some nice graphs on Micronutrients.
The Windows stuff I run is the Polar Precision software for the 720i that I use in the gym, and the desktop version of Fitday.
Chuckb, do you like the desktop version of Fitday better than the web version? It seems like the website is needlessly slow sometimes which almost makes it worth the $35 to buy the desktop version. thanks.