NOOK here - love it. Only drawback is the need for a light for reading at night. However, from what I understand, the color NOOK doesn't have that problem (different ink technology?). One thing to consider before buying any e-Reader is how often you'll use it. Two years ago, when I received mine as a Christmas present, the most popular books/authors were $9.99. I expected some increase in price over time but the prices have really risen. For example, Ken Follet's follow on to the Pillars of the Earth is almost $20!! I can get the hardcover at BJ's for under $15 and I'm sure the paperback will be a fraction of that.
If I had room to store more books, and didn't travel as much on business (I bring a minimum of two books), I might consider an eReader unnecessary.