for everyday computing, too many choices

I've been out of the hardware loop for about 3 years and too much has changed now with all the processor choices.

I just want a new pre-built computer to run my 3 monitors so I can easily use photoshop, dreamweaver, video (viewing/editing) and lots of browser windows all running at the same time.

For the same money, I can't figure out if everyday computing would actually be slower with dual xeons since it's mainly for large apps or why these 1.6ghz's cost twice as much as the 3ghz+.

If you were in the same situation what would you be looking for in a new computer?