I agree with Robert that 1024x768 is still a usable gaming res. My desktop 15" LCD is that res and I've been happy with it for the past 3-4 years. It's OK for Diablo II as well since 800x600 does not stretch too much.
I'm still contemplating getting a 17" LCD for the desktop, since I'm more frequently running games like Morrowind or NWN that have multiple resolutions. I'll just either scrap D2 once and for all, or start running in windowed mode.