Multiple lenses of course. I recommend buying a canon 17-40 L , 24-105 L , 70-200 f/2.8 L and a couple of tilt&shift lenses. :thumbup:
Tell me your budget. Honestly , I travel a lot around here while I'm in Europe. But when I arrive home I understand what an Idiot I am, and that I should stop wasting my money on gear and give up photography.
Overall I , as a tight budget photographer and a student, take the following.
This is all what I have:
Canon 18-55mm f/3.5-5.6
Sigma 70-300mm f/4-5.6
Canon 50mm f/1.8
Sigma 10-20 f/4-5.6
I take everything , sometimes except the Canon 18-55mm f/3.5-5.6.
Of course it's painful having to change the lenses outside sometimes and missing out stuff because you have a telezoom attached, but I think still my results are better than with a superzoom.
Every quality-conscious photographer should have min. 2 lenses. One to cover 17-70 (or inside) and one to cover 70-200 (or inside).
If you think that you won't have enough money to keep up for a couple of glass or want only one, I as a greatly skilled amateur photographer (just kidding, i'm much worse), would say:
The 50mm is not enough. Though a 35mm would be. Or get a superzoom if you don't want to hazel about "What lens?" outside. Or as I said to lenses.
Hope I helped.