I've been running on a 21" Mitsubishi CRT monitor for 5 years now, which gives off a tremendous amount of heat (MORE THAN MY 500W CPU!). I recently decided to purchase the Dell 2407WFP which is a widescreen.
From my monitor experience, you can NEVER go wrong with a Samsung flat panel monitor. They never get any burnt pixels in the long run and they last very long. Very costly though.
Viewsonic isn't a bad monitor either. Viewsonic, Dell, and Samsung are probably the top 3 on the list.
What's cool is that I bought my XPS 700 w/ 2407WFP monitor for $1200 after ridiculous discounts (35% off, 15% off, 2% off, $50 coupon). Without discounts it would have been $2000.
However, Dell is having HUGE delays with these systems. Ordered it on July 4th and ETA is August 15. To make up for it they are offering us an upgrade from Pentium D to the new Pentium Core 2 Duo, which is a huge plus. Still, these delays are ridiculous.
Sorry for the rant.
Good luck on your monitor buy!