Abus Bordo Granit X-Plus 6500. I own this and like it very much. The holster can be mounted most anywhere with the included Velcro straps or onto the water bottle bosses with the included hardware.
Get the best lock you can afford for the big city! Apparently no one cares!
'Normally' isn't the case with Abus. If you want to know something about the Abus 6500, there's plenty of information and reviews for it.ABUS lock mentioned above is a good example - the manufacturer is choosing the actual lock, so we have no choice in how secure it is/isn't. And normally the manufacturer doesn't indicate e.g. how many pins are used in a keyed lock, while we know the more the better.
I like the looks of this, an unpickable digital lock.