As a rough guide, all the major ports got a thumping. Manchester was hit, but as it's not a port, it could have been hit harder still. Surprisingly enough, the Germans never really caught on to striking railways and railyards. York and Crewe come to mind... If you look at the Bomber Command efforts later in the War, you can see a thought-through strategy for the paralysing of German industry and communications - even if it wasn't necessarily as effective as it might have been, given the limitations of the equipment of the time. But it did exist. You can search in vain for any equivalent strategy on the part of the Luftwaffe. Target selection, ports apart, seems to have been based essentially on throwing darts at the map... Thank goodness.