I use a number of packs. In particular I use the Jansport Orion 15 heavily. It has a bladder pocket and carries other items very well. It is not too long on my torso and has both a sternum and waist (more like ribcage) strap. For larger stuff I tend to use a REI Skree pack I bought 5 years ago. It is more of a traditional hiking pack w/no frame. The compression straps allow me to get good size loads down to size.

For just biking I use a two year old Camelback Lobo for my bladder and bike pump, etc.
-Duncan