Depending on the number of people, your best bet is to either take a Super Shuttle-like service or an Uber/taxi. Shuttles are usually around $16-18 per person to the DLR area; you'll probably have to drop off other passengers at other DLR-area hotels before you get dropped off, but for the price it can't be beat. If you have 3 or more people, it will probably be worth taking an Uber/taxi, since the price will be about the same and you'll have it to yourselves
We have always had good luck with Super Shuttle. They have come a long way when it comes to service and timing the rides so the wait is minimal at the airport for your ride to DLR.
