Just to clear up a few things:
Almost all monitors are "LED" monitors. This just refers to the backlight. Light shines from this through a filter layer generally called the "LCD" and THAT is what's important.
Different types of these LCD filters include TFT and IPS and more. All have different characteristics though IPS tends to be more expensive.
RESPONSE TIME is important so I recommend 5ms or less now.
In general, you should look at CUSTOMER REVIEWS.
Things to look for:
b) 5ms or less response time
c) inputs: DVI, DP, VGA or HDMI if needed (usually DVI is most used now)
d) HDMI with HDCP for BluRay (can have PC on DVI and XBOX on HDMI/HDCP for example)
e) good customer reviews
Things to watch out for with customer reviews:
- light bleeding
- shadows (uneven backlight)
- bad pixels
Also look for Warranties of 2-years or more if possible.