Collect (opening prayer) for daily Mass
The Collect is packed with profound theology. Fr. Z often analyzes the Collect of the day. It will get even better with the corrected translation coming out in Advent 2011. If you are praying the breviary, you can refer to the above site to get the new collects from the corrected translation (at least I hope that the site will be showing the corrected translation).
Update: This webpage is actually pretty neat. It contains brief commentary on the readings from the ordinary and extraordinary forms of Mass, and information on the saint of the day. Sort of like Magnificat.