What screen size and resolution do you use now?
My problem with non-laptop LCD's is there are not enough pixels per inch. 19" LCs' are generally 1280x1024 which is huge compared to my 19" CRT (18" viewible) @ 1600x1200.
(2) 17" LCD's @ 1280x1024 for under $300 would be what I recommend. sometimes you can even find a decent 19" under $150ea. CRT's are still better IMHO for image quality, but the weight, size are not worth the cost delta these days.
Dell does often have great deals on their LCD's and their DVI LCD line (xx07 models) is probably the best value on the market. Good enough for most gamers.
DVI is a type of input (cable) that provides a better signal. You need a video card that supports it which can be had for under $50 as well. Dual DVI is more costly. Any monitor that supports DVI also supports the standard D-sub as well, but you'll notice the quality if you switch between the two type of cables.
