I would recommend staying south in the spring and heading north as the weather "may" get better.

Fly to Athens so it will be warm when you get here.
Cycle to Patras, ferry over to Brindisi, via a stop over in Corfu, if you wish.
then kind of head to where you are flying back from.
You could head through a choice from, Naples, Rome, Milan, Venice
Then into France, or if you like mountains, Switzerland.

As you get going you will find out more about where to head for next , talking to people on the ground.

I have been touring around Europe a long time now and still I am finding places to go and see.

When you say "the sights", do you mean the normal tourist sights or , like me, famous mountains and gorges.

let us know a little more of what you would like to see.

I did a 3 month tour from Gibraltar back to the UK last year through Spain France Switzerland Belgium and Holland, kept away from big cities and enjoyed just seeing the countries, but you may want something different.

george