If you can afford it, get the 2408WFP. You will not regret it. The difference is night and day. S-PVA panels are prosumer-class, and TNs are the mass market. The 2408WFP also has a reputation for the best 1080P display in its market segment (Google 2408WFP and you can find a bunch of interesting reviews). I have a 2407WFP myself and am very glad I do. At some point, you can take the 2408 and simply use it in the living room, its connection suite is so good.
TN panels are good for certain things, but the image quality is nowhere near as good (color reproduction especially). They're best for gamers who want best response time with as little lag as possible. They're usually good business-task monitors too. I would guess out of all of them, Dell probably does a good job. The newer Viewsonics and Samsungs have not been getting good reviews lately. I've never actually owned a TN panel because it turns out my older Dell 2001FPs are S-IPS panels. The only reason I'm such a know-it-all now is because I've been spending months speccing out 24"-26" displays for an upgrade.
And, by the way, there is a Lenovo 22" monitor that does true 1920x1200 and has a really stunning display. It goes for about $500. It's the Lenovo L220x. It's also an S-PVA panel. I almost bought it but snagged the Dell 24" instead. Interested?
Here it is.