For the landscape and travel photographer who wants to travel light, rather than settling for the ubiquitous, ever-wider-range (but often hopelessly slow) zoom(s), I would suggest going against the grain and starting with a 'classic' set of two or three prime (fixed focal) lenses that are evenly spaced in terms of their angle of view (AOV):
For a TWO-lens kit, I recommend a moderate wide-angle (~35mm eq.) + a medium telephoto (~85 - 135mm eq.).
For a THREE-lens kit, I recommend a wide-angle (~24 - 35mm eq.) + a 'normal' or short tele (~50 - 85mm eq.) + a telephoto (~135 - 200mm eq.).
With these two or three lenses, you will have 'all bases covered' with great image quality, and will never be in doubt as to which lens should be on your camera at any given time. Even more importantly, they will spur you to 'pre-visualize' the scene, and not give in to the temptation to plant yourself in some random spot and 'frame by zooming'.