I recently purchased a 19 inch monitor and I've been playing with the resolution trying to find the one that I'm most comfortable with, my question is: does aspect ratio matter? According to the manual that came with the monitor and most of the info I've seen on the net, the recommended resolution for a 19 inch monitor (18 inch viewable) is 1280 x 1024, but that's a 5:4 aspect ratio, the specs for the viewable area of the monitor are 365mm x 275mm, a 4:3 ratio, wouldn't it be better to set a resolution with the same ratio such as 1280 x 960? or does it not matter and I'm putting WAY too much thought into this?
No aspect ratio is 'better' than another. Things do look slightly different with different ratios, but the aspect ratio is always very close in all the settings. So I would recommend going with the highest resolution that your monitor can support with a refresh rate of 75 Hz or above, but not to the point where you have trouble reading things because they are too small. That is just a preference of mine though. I like to fit a lot of information on the screen at once and I don't like seeing pixels. Others like havings everything large on the screen and therefore lower relolutions are preferable. When using full screen to play games or watch movies, things are always the same size, but higher resolutions are much clearer. Most of this is common sense, but my point is that it is all a matter of preference and it doesn't matter. You are correct that different aspect ratios change things, but often not as much as changing the settings on your monitor to stretch the screen. So just use trial and error and use what you like and don't worry about aspect ratio.