Yes, the Dell 2001FP appears to be highly rated. Depending on the sale, it can be had for a very good price. I think it went for as little as $800 recently. I didn't know about ghosting in Halo, though.
Your main concerns with a gaming LCD should be a low response time (16ms is the lowest available) and DVI input. Keep an eye out for good black levels (so the backlight doesn't shine through "black" pixels and make them look gray), consistent lighting, and a good deal-pixel policy, too. And make sure your video card is powerful enough to play games at the LCDs native resolution. Consider a much cheaper 17" 16ms LCD if your card is more comfortable at 12x10 than at 16x12.