The Default Devotional

I've been realizing the past few weeks how great it is to always have a devotional that I can default to when I'm stuck in a rut or between other devotional studies. Mine is "My Utmost for His Highest," by Oswald Chambers. I picked it up (once again) after deciding that a larger reading plan wasn't really feeding me like it used to. After a couple weeks into My Utmost, I feel refreshed and nourished by the Holy Spirit.

So what makes a good Default Devotional? Here are a few things I came up with...

1. Short amount of reading. You can always go longer with something short, but you can't always go shorter with something long. The short readings allow you to "take a break" from long devo readings without taking a break from devos.
2. Continually challenging. I've read a lot of these one page thoughts before, but feel challenged in a new and fresh way each day.
3. Moves you to prayer. Usually when a devotion style gets tired for me, it's because I am focusing on what is being said to me instead of what I have to say to God. My Utmost always pushed me into an honest time of prayer because the time would feel incomplete without it.
4. BONUS: Take-anywhere format. I didn't think this could count as an actual criterium, but it is definitely a bonus if you can take it wherever. This way you can give your devo life a zap without being tied to one spot. It really helped me when I saw that I could buy My Utmost as an iPhone app, and take it with me everywhere.

Anyone else have a default devotional?