London and Paris, Peru or Iceland?

I had to hand in my vacation request on Friday. If approved, I won't be taking any time off until June (the next five months will be project heavy at work). If budget permits, Andrew and I are dreaming of a few options for travel this year:

London and Paris - To take advantage of an Air Canada deal offered to Andrew, we're thinking of cramming these two cities - including a Britney concert stop in London - into 7 days. Crazy I know, but there's no other way we love to travel.

Peru - I just can't get this place outta my head.

Iceland - Read an interesting article in Metro's weekly Travel section, which I love, about how Iceland is suddenly a cheaper and travel hot spot.

The next step is to budget out these three possibilities and see which one, if any, are feasible. But for now, I shall keep on dreaming. Which shall it be?