If you want the most bang for your buck you can't beat a CRT. You can get a great looking screen for incredible prices these days if you don't need an outrageous size.
While I've been staring at a TFT for almost a year now and love it, I do want to point out that there is a catch when you decide to go for the flat screens. While a CRT is happy to switch between resolutions and show them all with a fair sharpness, a TFT has a fixed amount of pixels which gives it a 'hardcoded' resolution. This means that at anything but this setting the screen will interpolate pixels to give you what you're asking for, leaving you with a slightly blurry screen. For most 17" monitors this resolution will be 1280x1024, but for most 19" monitors it is also 1280x1024. This means that as you switch from one to the other you will not have any more room to play with on your desktop, it just looks bigger.
Also if your eyesight isn't perfect, or you are uncomfortable staring at very small print for a long time you might find the standard setting on a 17" TFT too fine for your liking. My advise therefore would be to check thoroughly if the 'standard' setting on the TFT that you're after is one that you would be happy to look at for longer times, especially when viewing Internet pages or Word documents or stuff like that. In the same way your games would also only look their best in this fixed resolution, so check that this is what you want before you buy.