I had a 2001FP before the U2410 I have now and all I can say is that gaming on it is fantastic.
For a short period I also had a T240 (2ms TN panel) from Samsung and, while the response time was blistering, the colors on the IPS are much better. If you can get a U2410 on sale here (http://www.dfsdirectsales.com/dell/ctl641/cp57131/cl2/monitors
), you can get a great deal.
The 2412M is also an excellent panel, though is has a slightly smaller color space, I think, than the 2410. Though, it's also cheaper. I don't think most people (myself) would notice the enhanced color unless comparing a 6-bit IPS to an 8-bit IPS side by side.