Granted screen resolutions and the like have probably moved on since this question was asked but here's what I currently understand:
Most desktop screens are full HD (1920px x 1080px) with 4k becoming more common (3840px × 2160px), laptops are usually 768 x 1366px (some have HD screens, and then there is the macbook pro). On top of that there are a wide range of mobile devices with varing screen resolutions (and some with quite high resolution that display as a lower resolution).
Based on that information, if you are happy having multiple columns, I would look to have a "wide" design of approximately 1900px (if most of your users are using desktops). If on the other hand you are looking at standard 2 or 3 column layout I would consider setting a max width (~ 1680px seems common, but this would depend on your content). Obviously it will need to deform nicely for smaller screens.
As always if you can get the screen resolution of your users, it would be best to design your site to look great on the more common resolutions, and deform nicely for the rest.