First, you guys are approaching this wrong. You're saying "I want a computer" without figuring out what you're going to use it for.
1) Why does she want a flat panel monitor? Because they look cool? They certainly don't have as good a picture as a good CRT, and they cost a lot more. Unless space is a super premium (I doubt it) there is absolutely no reason to go with a flat panel at this point.
2) You say you don't want to build a computer, but you then say you want to get one and then install parts. That's pretty much all building a computer is, is installing parts. Why not take the extra step and get quality the only way you can without paying through the nose.
I would certainly not recommend anything from Best Buy. They run minimum specs at maximum dollars there, and any other retail outlet.
If you MUST buy prebuilt, Dell is as good as anyone else, which is to say not very. You need to accept from the get go that your computer will not be as powerful or reliable as you could have for the same money if you built.
At any rate, stick with a CRT. It's still the superior technology. Just because something is new doesn't mean it's better
