Zurich at $538 RT

You've got a tough call to make, Chicago...

Option A: Stay in Zurich, wandering around the gorgeous Old Town, hopping from museum to museum, and enjoying the best chocolate on the planet.

Option B: Use the city as a starting point for some ridiculously scenic train rides around Europe, like the Swiss Alps-bound Glacier Express. Or this one that drops you off in beautiful northern Italy.

Then again, you could always do a little of both... :-)