i think a lot of people here have widescreen, in terms of productivity its a lot better, helps with larger thigns and is more natural to turn your head left and right than it is to go up and down.
Ive got a Hyundai N91W 19" Wide and i couldn't ask for more from it
One more for widescreen. If you play older games, they don't support fullscreen wide resolutions which is kind of annoying, but other than that, they're amazing. Better for new games, better for media (movies, pictures), and better for work.
and don't forget most video cards are capable of turning the picture 90 degrees, so you can have a portait layout as well, for reading or photo editing.
You'll probably need a 3rd party stand, tho. Most monitors come with junk stands.
My opinion, go with a standard 19", it'll look a lot bigger than a widescreen.
If you want a 19" monitor, go with standard LCD, if you want a 19" widescreen, you'll have to go up to size 22" or so to get the same total amount of viewing area.