Personally I prefer asus for their reliable customer service. But LG and samsung are big panel manufacturers so when you buy from them you're buying from a company that is working with their own technology rather than someone else who just bought it from them to use in their product(s). Samsung has some sexy stands and bezels as well. Although Dell monitors are good and have outstanding stands on any decent model.
As for acer I can't really say despite owning an acer monitor. Not a huge fan of HP for their iMac style monitors with limited capabilities on the stands. Never been sure why BenQ uses VA panels for gaming monitors when TN panels are better for gaming with naturally lower response times.
But in the end I'd say its all on service and reliability so asus takes the cake for that one.