Where would you go?

How about eastern Europe. Bucharesti is an elegant old city, and Stara Zagora, Bulgaria will give you an unforgettable experience. Do you need details? One thing to consider is that the costs are much less than in western Europe.

I would go to Croatia along with side trips to Bosnia and Montenegro.

Except for Eastern Europe, I have been to all the potentials you listed for your next trip. From the places you have seen so far, it looks like you tend toward cities and larger towns. For a 3-week trip, I would recommend doing something that would be very different -- concentrating on one general area and immersing yourself -- maybe even renting a car to get around. Here are 2 places not on your potential list. 1.) Sicily. We drove around with our daughter in Sicily in 2009. There are spectacular Greek and Roman ruins as well as great beach and mountain towns. I didn't expect it to be so charming and rugged at the same time. 2.) Iceland. There is no place like it on Earth. Everyone should see Iceland, and not just Reykjavik. We will definitely go back with more time to explore this unique country. Here are 2 that you did mention. 1.) Scotland. The major cities are interesting and fun, but the Highlands are magical.
2.) Northern Spain. We stayed in San Sebastian and took a bus to Bilbao. What we saw along the way was totally unexpected and left me hungry for more. I hope that helps. So much Europe, so little time...

Natalie, planning is such fun... I have been to all the locations you have as well as all you are considering, and since you have not been to Eastern Europe I would definitely recommend taking that route..... Romania is beautiful and a unique culture, as well as Budapest, Prague and Poland is also a great place to visit. All of these countries will be cheaper, as already suggested. Especially Romania... the Transylvania area is a great area to visit. Travel by car is very easy there. Iceland sound great as well. I have not been there yet, although I do have a friend who is a fellow photographer who lives there and has encouraged me to visit... I think that needs to be next on my list.
Turkey is also a wonderful country with exotic people and lots to see.

Wales is awesome. Scotland is awesome. Denmark is awesome. Okay - that may sound like simplistic twaddle, but it is TRUE. You don't mention that you have been to the Loire Valley. It is amazing. The Dordogne is a mellow slice of wonderfulness.

I'd go north to Scandinavia - Denmark and/or Sweden. I also have to put in a big vote for Portugal - I loved it! I'm considering this very question and although I haven't been as many places as you, after Portugal and Spain I'm looking for something a little different than Western Europe. I'm considering The Netherlands (still Western Europe, I know), Denmark, Sweden, or Hungary......and I'm leaning towards Scandinavia or The Netherlands. Croatia is the "in" spot these days, which puts it lower on my list, frankly.

One great thing about Scotland (among LOTS of great things about it), is that you can experience the cities and larger towns and the small villages and countryside in a nice, compact area. There are several good places to base yourself for 3-7 (or more days) and do day trips. Inverness is one of my absolute favorite places! You get moutains, ocean, farms, cities, etc. in one compact, lovely- no beautiful place with friendly, open locals, good whisky, and good food. You could fly into London, use the train to work your way up the coast and see more of the UK - York makes a great 2 or 3 night stay, spend 3 or 4+ days in Edinburgh, take the train to Aviemore or another village in the Caringorms, for 2 or more days. Then on to Inverness for as much as a week, then maybe Isle of Skye or Oban, or work your way up to Orkney. Then perhaps back down to Glasgow. If you perhaps skip the Islands and you could add the Snowdonia area of Wales- it is fabulous!!!!

You can't really make a bad choice. I'm prejudiced (I'm of Irish descent), but I'd recommend Ireland. And with 3 weeks, you could certainly include Northern Ireland & Scotland as well. All beautiful countries with lots to see and wonderful friendly people.

I would pick one general area, and then focus on it. Based on your post, some options would be: Scandanavia, with a side trip to Estonia or ST. Petersburg (a ferry ride from Finland). (You may need to obtain a separate visa to go to Russia; I believe your passport is sufficient for Estonia, Latvia, and/or Lithuania) Budapest is cool, but it is becoming westernized (Subway, Burger King, KFC are everywhere). Do Vienna, Budapest, then fly (or night train) to Slovenia and Croatia (Lake Bled, Split, Plitvice, Korcula, etc.) A trip starting in Spain and ending in Portugal would be good. Add a side trip to Casablanca or Marakesch, Morrocco. Any of these could be done as a solo traveler.

I wish I knew more about what you liked about the places that you've been, but since I don't I'm going to tell you to go to Scotland. I would go to Orkney in June. First, it's a wonderful magical place. Second, in June there wonderful bird migrations and third, there is a festival. http://www.orkneyfolkfestival.com/ For more info on Orkney check out these two websites. http://www.visitorkney.com/index.asp and http://www.orkneyjar.com/ I love Scotland for many reasons. They include the friendliness of the people, the fascinating history, the beautiful landscape, the castles and archeology, the music, the whisky, the seafood, the stories and so much more. PAm

I'm with Tom on this one. Spend your 3 weeks discovering the amazing sights and experiences Scotland and Ireland has to offer.

Because of the Spring timeframe. I'd probably start in Croatia and work my way north. Depending on how much area you like to cover, a swath up through Budapest is doable. Alternatively, you could also start in Turkey and work your way toward Croatia.

Turkey! I went to Istanbul fo rthe first time this year and fell in love with it. Then I went back and travelled down the Aegean coast (on a RS tour). It's beautiful and the people are lovely.
Plus, once you cross the water you'd be in Asia!

Portugal. Beautiful, nice peope, so many places to explore, cheap, great food ... I loved Portugal much more than I expected to.