This place is a little out of the way in the northernmost neighborhood of Manhattan, but it's ON THE WATER with spectacular views of the GW Bridge, AND sunset. It's a hotspot, but less busy on the early side. They even have decent food. It also has an interesting history, though it's notoriety seems to have faded over the past couple of years. Accessible by subway (the A train), or there's valet parking on site for $20. And of course, you can always take a cab and then uber home. The views are well worth the spendy drinks.
http://www.lamarinanyc.com
http://www.lamarinanyc.com