Monitor Review Sites:

X-Bit Labs
Flatpanelshd
PCmonitors
Hardwarezone
Anandtech
Bit-Tech
Prad.de
Extremetech
TrustedReviews
Testfreaks

Previously good, but now rarely updated:

BeHardware
Hardware.fr (BeHardware French Site)
Tom's Hardware Guide
Tom's Hardware Guide France (Translated)

News Sites:

Digitimes - main news
Digitimes - news from other sites
Engadget
Flatpanelshd
Aving.net
Cybertheater
DisplayBlog
PCmonitors
LCD 24/7
Prad.de
 

Other Related Sites:

Flatpanels.dk (Danish) - Excellent site for Danish readers
Monitor Calibration and Gamma - useful guide
igadgetlife - Product info and reviews aggregator
 

Forums:

Overclockers.co.uk
[H]ard|Forum
Widescreengamingforum