Quite similar to this question, I'm in trouble of the same problem now. I'm trying to set up dual monitor on my SONY CS36H laptop, and I bought Acer S231HLbd last Saturday, but have been struggling with solving to get the text be sharp in these days, searched a lot, tried a lot, including all the methods in the best answer of that question, I even did more, like reinstalled NVIDIA driver, reinstalled Windows 7, tried to set gamma to some darker to let the text shadow gone. Turn off and on the clearType a few times. Changed the location of VGA cable, split the power cable and VGA cable as far as possible. Issue still there. also the screen is too white, and not healthy for eye ..
Arial font could be kind of sharp, but bold font are too fuzzy, and more other fonts look fuzzy.
I was hoping to buy DVI transistor, but posts show that it helps little for 1920x1080.
What I didn't have time and chance to do is to take the big stuff to office and try whether it is because of my laptop's video card issue, or to find some other LCD to replace and see whether that would be sharp.
Now, I'm totally exhausted .. what's left now is changing another LCD?