I second the recommendations for an ultrawide. Of the choices given, I think I'd recommend the 17-55. The f-number is much faster than the kit lens, and most people use this angle of view a lot. On the other hand, if you are more of a telephoto person and you like compressed portraits, the 70-200 f/2.8 L would be excellent. It's certainly a much bigger and heavier lens. Build quality, focus, etc. are a step up.