OP,
Avids are decent (v) brakes; it's unlikely to be the brake mechanism in/of itself.

Glancing at your pictures, I'd say your front brake pads are certainly well-worn, so a question: do your rims have those wear-indicator groove thingies on them? If they do, look at your brake pads -- especially the left: is there a raised ridge in the centre?

If yes, what is likely happening is that the ridge is sticking in the wear indicator groove and so the pad won't release freely. It's a common problem; v-brakes work best (can be balanced best) with low spring tension. The solution is simply new brake pads (it looks like you need those anyway; new cables would be a good idea as well).