the problem with getting a 24" tv instead of a pc monitor is that because you have other functions built in (such as a tv tuner) you might get a lower quality product instead of if you bought a monitor. if you need the tuner go for it, if not i'd stick with a monitor since you have a lower budget.
1920x1080 should be the lowest resolution you go for. anything less is cramped.
at that price point you're probably looking at a TN panel (or if you're lucky maybe a VA or e-IPS, these are better but might be higher priced). Personally i prefer having a decent resolution and the best possible picture quality. crappy monitors aren't a joy to use at all.
Not sure if this is obvious, or matters, but I will be using it for TV via cable wire, not through my computer. Is it really worth using the extra space and just using each one separately? I currently have a Dell 22" monitor which is good, but this is for my college dorm so space is rather confined. If the quality that that noticeable, I suppose I wounl't mind using both screens...
Yeah, if you are getting a TV and computer monitor all in one, thats fine, however as the other poster said, i'd got with a 1080p resolution. You'll never use 1080p on your TV anyway unless you watch blu-ray movies, but 1080p is a great resolution for a computer screen. Less resolutions are also fine, but if you go for a 1080p TV, not monitor, you might save money on the TV and it will expand your selection by huge amount on what to buy from.
For example, I'm not sure if this brand is good, never had it, but here is an LED-LCD for around $200
Yeah yeah, plasmas technically are considered to have the best picture due to contrast, best blacks...etc, but a good LCD, LED, or DLP will have a contrast that good enough that you would really need to pay extreme close attention and compare the two side by side to notice any difference in the blacks (At least for me I do, I'm not a videophile). I'm not sure if LED's are prone to Burn-IN (Haven't done my reading up on them yet), but LCD (LED-LCD) is the only TV (I'm not sure about a real LED) that you can get of a small size, doesn't burn-in, makes a great picture
another thing to note, if you are really tight on space you could also keep your 22" inch monitor you have now and instead get a tv tuner card for your computer (using your computer as a media player device).