I use Consolas 10pt on Windows, and have found it to be extremely legible no matter what my resolution -- or more specifically, the monitor's DPI -- was. This is on dual 19" 1280x1024 monitors, my home 19" 1440x900, a 15" laptop at 1024x768 and a 15.4" laptop at 1440x900 (which was the only one where I even considered adjusting the font size).
Now, where it gets tricky is in a Mac world. (Yes, I did a Bad Bad Thing and copied the font onto my Mac for XCode.) In the Mac world, I found 10pt to be completely illegible no matter what monitor I was hooked up to. For Mac, I adjusted myself up to (I think) 12 or 14pt. However, on-screen, that wound up being about the same size as 10pt in Windows for me, so it was the same net all around.
I used to love ProFont. Until I discovered Consolas.
