The easiest way to find out which is the best is to look thyem up on www.newegg.com and read the specs.....Newegg.com uses the exact manufacturer's specs.
Things to look for :
1. IPS or TN panel...IPS being easier on the eyes.
2. Pixel pitch...the lower the better
3. The connectors on the monitor, with reference to what you intend to connect them to.
In this case the AOC is the winner if you can deal with only VGA and 2x HDMI connectors. The ACER doesn't even list pixel pitch or warranty...so I'd avoid that.