DV Hardware have published the first part of their LCD display buying guide:

Play games? Well, you may want your contrast to be set on the higher end and the response time of your LCD monitor (especially the gray-to-gray) to be as fast as possible to prevent motion blur (i.e., Ghosting). Graphics and imaging LCD monitors generally do not have the fastest response time, so if you're a hardcore gamer, you will have to make some sacrifices. Currently, having the best graphics monitor while also having the fastest response times, is not possible. However, you could purchase a high-end monitor for graphics and still enjoy your PC games with little issue. It all depends on where your enthusiasm lies.

The typical all-purpose LCD monitor is splitting off into categories and other terms which specify the user. LCD monitors for PC gamers is something new which has been more prevalent in 2006. This has been most in part from PC gamers who have expressed their opinions on playing games and LCD manufacturers who are listening because in order to have a successful product, you must have a product which meets the consumer's current requirements. PC gamers make up a large segment of LCD sales, and having specific monitors for those gamers, is a great way to further the technology and research.

Overall, if an LCD monitor has a lower nit rating, such as 250 cd/m2, but has a high contrast ratio, you could still be getting a quality product. Be sure to put a high contrast ratio at the top of your ingredients for an LCD purchase.