Jason Romero sends me a link to a great article by Gary Voth about ditching your SLR's consumer zoom lens for a classic 50mm prime lens: http://vothphoto.com/spotlight/articles/forgotten_lens/forgotten-lens.htm
If you are like most photographers just starting out with a new 35mm SLR, chances are it came with one of those ubiquitous 28-80mm (or similar) "consumer" zooms. In the last 15 years these inexpensive lenses have all but replaced the traditional 50mm prime lens as the starter optic for 35mm photographers. The 50mm lens, once the mainstay of 35mm photography, has been all but forgotten by today's photographers. [more]
I agree but I personally prefer a wider 35mm lens (such as my handy Summicron 35mm for the Leica M system) to the 50mm that Gary recommends. I find a 50mm is just a bit too "long" and while it's good for capturing intimate portraits, it makes it harder to understand the context in which the photograph exists. A 35mm also forces you to get that much closer which is always a good thing.