One lens will not fit all requirements.

If you are also interested in macro, then I suggest that you buy the 100mm f2.8 macro first. You can add other lenses later.

I had given the same suggestion to Abhishek and you can see his images in the others section. You have the option of buying a Canon 550D body which will come cheaper. You can also look at options of buying a body second hand from people who would be upgrading.

I would repeat my suggestion that don't blindly buy equipment. Build up your collection slowly. Buy only the good things.

So first buy the EF 100mm f2.8 macro lens. It is a great lens. And buy a body based on your budget. There were good deals on 550D body. You can also check for 600D body.