My preference: 18-70 and 70-300.
I have been told that 18-70 is better than either 18-55 or 18-135 and the price (as well as size of lens) is not in killer league, unlike the 17-55 f2.8.
70-300 too, is said to be a better lens than 55-200, better in terms of image quality and, of course, gives longer reach.
This combination is, I feel, a good compromise between the cheap and the expensive. Of course if lens size and money no problem, sure the f2.8 lenses are better.
To me, having two lenses instead of one kiasu 18-200 everything can do lens is not that much of a hassel. Sure, might miss a shot now and then, but hey, that's life... gives you interesting stories to tell about "the one that got away".
It is only when you have to carry around 4 or 5 or 6 lenses instead of 1 or 2 that I consider too troublesome.