Some smaller cities you might like:

Around London:

• Brighton: Cool beach town
• Cotswolds: North of London, gorgeous with rolling green and thatched roof houses. rent a bike!

Berlin

• Berlin’s cool on its own. Stay and hangout in East Berlin. Awesome art scene.

Prague

• Cesky Krumlov is a nice littele city

Amsterdam

• If you fancy getting out of the big city, the small town of Noordwijk is on teh beach, an hour from Amsterdam and has a branch of the Flying Pig Hostel.

I really recommend you Switzerland. The Alps are amazing (Matterhorn, Jungfraujoch) and also the ski resorts are awesome. Ok, if you’ve been in the Rockies (Whistler Banff) it s not gonna be that impressive but it s still worth seeing it. Im swiss and I ve also been in the wonderful Rocky Mountains but I still prefer the Alps

From Munich it is easy to visit Salzburg (a Bavarian train ticket has a special rate). Hallstadt is a bit beyond Salzburg, but the scenery is beautiful.

You will be too late for the tulips in Amsterdam, but it is still a nice visit. They have a Netherlands museum pass that covers most of the best art museums. Haarlem is a short train ride away and is nice (some people stay in Haarlem and take the train to Amsterdam because Haarlem is less expensive). The Hague is also near Amsterdam and has some excellent museums that the above pass will work at.

From Barcelona you can easily visit Montserrat which is up in the mountains and very scenic.

I would consider making your trip a little later in the year, when prices are usually lower. and everyone seems to like the Christmas fairs that start in late November and run until just before Christmas. But I’m not sure you could hit both Octoberfest and the Christmas fairs.