Since Hoboken's waterfront faces east, the best spots are less about watching the sun dip below the horizon and more about seeing the amazing colors light up the Manhattan skyline. For that classic view, head to Pier A Park or Pier C Park. The open space gives you an unobstructed look at the city as it catches the evening glow.
If you want to see the actual sun setting over New Jersey, you need to get some elevation. The best public spot for this is Castle Point Lookout at Stevens Institute of Technology. From there, you get a great panoramic view looking west over the town.
For the quintessential Hoboken sunset, head to Pier A Park. Its large, grassy lawn provides an unobstructed view of lower Manhattan as the sky changes color.
If you want a different perspective from up high, the lookout at Castle Point on the Stevens campus is the best spot. The elevation offers a stunning panoramic view you can't get anywhere else in town.
Maxwell Place Park is another fantastic option, often a bit less crowded than Pier A. It gives you a beautiful view from a little further north along the waterfront, complete with a small beach area.