How can I make fonts look good in an LCD monitor ?

The VGA connection should be fine; I have DVI and when I switched from analog, the difference was pretty minimal, to my eyes.

Is it just the fonts that are blurry, or everything? If fonts only, then this almost certainly suggests that running the ClearType tuner again would solve the problem. But this applies to all displays, so if one is good and the other is not, then this isn't it.

If everything is a little blurry, then this suggests one of two problems -- the first, you report trying, which is that the display adapter is set to a different resolution than the native resolution of the LCD monitor itself. Your display adapter should probably be able to drive 2 monitors (the built-in laptop monitor and the external monitor) at once. You should be able to set their resolutions separately.

Assuming Windows XP: Start > Control Panel > Display > Settings > at which point, you should see two monitors listed in a dropdown. Set them to their native resolutions there (using the slider bar, usually all the way to the right), and save.

If you do have the display resolutions set to their native resolutions for both monitors, then it's possible that your external monitor is messed up. A quick test would be to run the on-screen settings, usually from a button on the monitor itself. If what is displayed there is sharp and what is displayed from Windows is not, then this points to a problem with the display driver. If everything, even the on-screen display is blurry, then perhaps the monitor settings are messed up -- usually there's an option to restore to factory settings -- try that.

If that doesn't work, I'm probably out of ideas, unless you have further information.

I had the exact same problem, main symptom that something was screwy was that the menus on the monitor were really sharp but text from the PC was blurry (Win7Pro / Dell Lattitude E6430 / NVIDIA NVS 5200M / LG E2240S external monitor). I reset the monitor to default settings - no change. Reinstall latest graphics drivers - no change. It got fixed after went to Start-Control Panel-Display Adjust Resolution. I then messed with this for a bit and suddenly the text looks great! (I think I changed from Extend, to Duplicate, to change to lower resolution, change resolution back and go back to Extend). It's a really, really big difference, so keep trying and don't put up with the blurry stuff. And maybe the monitor reset and reinstall drivers helped on the way, so try the same sequence.