Need help with monitors, its tax time and in the market for a new one.

Okay beforehand here are some system specs:

Intel Q8200 2.33GHZ Quad Core
4GB DDR2 800Mhz Ram
EVGA GTX 275

My current monitor is a Dell 17' that operates at 1280x1024

The video card isn't the best but it does very well on most games that I play and has really stood up over time. But on that point, I know the video card is the most important thing when it comes to playing games at higher resolutions. My main questions are primarily about resolution as some monitors have weird resolutions. I know 1920x1080 is full HD and most 24 inch monitors support that resolution natively. Are resolutions like 1366x768 or 1440x900 worth getting?

If anyone wants to post links with good monitors Id appreciate it, as well as any feedback. Im trying to keep the price range at $200 or less.

Also HDTV pros and cons as a monitor? I know the resolutions arent as good as a dedicated monitor of the same size, but it would be nice to have the ability to hook up DISH, my Xbox and computer all to one screen and just toggle inputs.