Best lens for Nikon d40?

I will be traveling to the UK and I will be taking my Nikon d40 along with me. I will be visiting many places there such as London, Edinburgh, Manchester, Chester, etc. I'll be taking scenery shots and self portraits with friends against backgrounds.

I would need a lens that isn't very expensive yet good for every day usage. What would you recommend?

1. What is your budget?

a good all-a-round lens is the Nikkor 18-200mm AF-S lens which costs $600

Actually any AF-S lens, new or used.

I would take a 10-24 mm wide angle to capture those amazing land and cityscapes during your travels

The other lens I would include is the 18-200 mm VR