After looking for comfortable armored pants for a while, I decided to go a different route and have so far been very pleased with the result. For armor, I slip on Knox Cross shorts and a pair of Icon Knee/shin guards. This armor should stay in the proper location better than the pads provided in some of the armored pants.
I've found the Knox Cross shorts to be extremely comfortable. In fact, I could probably wear them all day and not notice them which is surprising considering the protection they provide. The Knee/shin guards are comfortable but I don't think I'd want to wear them all day.
For pants, I went with the Icon Victory pants with the black stretch/ventilation panels. I'm happy with the comfort of these reinforced jeans as well but I wish they didn't have a button fly. And like someone else mentioned, the inseam on these are quite long so if you are a little shorter you might have someone hem them up a bit.
The nice thing is all this protective body armor slips on quickly, is comfortable, is not noticeable under the pants and allows you to choose many types of riding pants without worrying about the fit/effectiveness of included slip in armor.