gamingwoop :
pasow :
depends on how close to the display you are and the size of it.
with higher resolution comes a smother image, where AA is less important, and everything is better defined.
at the lower resolutions you will need more AA in order to get a smooth image and everything is less defined.
now if your display is 1440p, i would stick to its native resolution and reduce the eye candy till you hit a frame rate you like. that will almost always look better than up scaling 1080p. (i hate blurry things)
Ok well 29in 1080p or 27in 1440p...my GPU may not handle 1440p on ultra, but it will handle 1080p on ultra.
if you have the R9 290x that is listed on your profile, you can handily play games at good frame rates at 1440p with maxed settings. you will dip below 60fps from time to time, but the majority will be at 60 or higher.
http://www.tomshardware.com/reviews/shadow-of-mordor-performance,3996-4.html
http://www.tomshardware.com/reviews/radeon-r9-290x-hawaii-review,3650-16.html
if your buying your monitor purely for gaming, i recommend looking in to a FreeSync monitor or a high refresh rate one (in which case, aim for 1080p to avoid the price premium and it will be easier to drive). they will have better motion tracking than a 60Hz display.