Cheapest tickets to Europe?

There really isn't. Just make notes.

Airline rates fluctuate with the time of day, day of the week, time of year, departure & destination cities, the weather, who won the super bowl, if you are wearing blue or green when searching...you get the picture! I open several tabs, one for each city I am considering - if your dates are flexible most sites can give you rates for several days at once. If you see a good rate - grab it - it won't be there for long!

In other words, keep doing what I am doing. Every airline, as well as Kayak, asks you to put in the dates you want to travel and then it lists your options, cheapest first, for the departure date. There ought to be a site that enables you to list the dates and make the cities the variable instead. Dates and departure sites are not an option for me, but destinations are. I only have a few times a year when I can take vacation, flying out of Atlanta, but I am open to going to any of several places. There ought to be a simple way of tracking them in one site.

http://www.kayak.com/explore/ATL/20140901,20140930/

Switch the dates around, I forget what I used.

Thanks, Ed. That's a good starting point for future searches.

Happy hunting. Remember that additional places, trains, etc. across Europe are not free, so it pays to fly to and from cities you want to visit, and not necessarily the same one. For instance, if you had to get back from Rome to Paris, a discount flight (booked ahead) would often be cheaper than a train ticket (even if booked ahead).

Try ITA Matrix. It allows for searches within a radius of a destination.

We got a winner. I bookmarked Matrix-Search along with Kayak Explore, which was there all along but I never noticed it before. I tried Pinups but gave up on it.

For further reference, Skyscanner also lets you do comparisons by selecting Anywhere or Everywhere for a destination.