I guess I don't have a collection as much as a series of bags that I still have because I have found a better one and have not got rid of the older ones.

I am somewhat obsessive about rolling computer bags - my current favourite is the B&R306X4.

I don't get too excited about other types of bags so long as they just 'work' but I guess I am hung up on packing cubes and the like - to put inside the 306X naturally - and to make carrying all the various computer and electrical bits I need easier to carry.