Well you could best fly into or out of Zurich if starting or ending in Interlaken - just a short train ride from Zurich Airport and then work you way north to Munich or Berlin and fly back from there.

Train connections are excellent to all those places and if going to the Interlaken/Jungfrau Region then trains are best IME as beyond Interlaken car travel is severely restricted and you must take trains or cable cars into the higher Alps. Interlaken is a nice cozy city for a base though many prefer more remote Alpine towns like Wengen, a perpetual favorite for the older crowd seeking solitude and simply awesome views of the glacier-drenched Jungfrau Massif. Grindelwald and Lauterbrunnen are two more lively towns for younger folk with similar views from their hotel balconies.

Trains take you to all those lovely places from Interlaken-Ost train station.

Investigate a Swiss Pass that is valid in full on trains to all those places and more as well as around Switzerland and to the Austrian/German border if going to Munich or Berlin.

You may want to spend a few days in Munich then take the train to Berlin if you really want to see that amazing to me and most interesting city but it is farther afield for you and in 10 days I would probably concentrate of Interlaken and Munich.

Munich especially offers many nice day trips, like to Salzburg, Austria, one of Europe's loveliest cities or to Mad Ludwig's castles at Fussen, Dachau Camp, etc.

For lots of great info on Swiss trains and passes and German trains I always spotlight these IMO fantastic sites - www.swisstravelsystem.com; www.budgeteuropetravel.com; www.ricksteves.com.

Would help to know what your interests are.

Are you into just outdoors - hiking, etc - or do you want to see museums and castles, fine dining?????

Recos will depend a lot on your interests and the make up of your group.

Instead of Munich from Switzerland you could see a bit of Austria - taking trains to Innsbruck - in the heart of the Austrian Alps and then from there to either Salzburg - both Innsbruck and Salzburg are quick train hops to Munich, a city that may offer more air fare options than Salzburg or Innsbruck and a city that you can see the main things in a day or two.

Great, thank you for the information. That certainly helps!

Our interest vary. Certainly the outdoors in Interlaken, but then we would like to taste the culture a bit - great food and wine/beer, museums, castles, and any other "must see" aspects of some of the more major cities.

Also, although we'd love to see areas of both Germany and Austria, I think only one is doable given our 10 day time frame. Is either more convenient from Zurich? Or is either more of a "must see" than the other?

great food and wine/beer, museums, castles, and any other "must see" aspects of some of the more major cities.>

then I would go to Munich which certainly fulfills that desire and perhaps day trip from there for a day to Salzburg, also such a city. Base in Munich.

Let's start with your must see - Interlaken. Here are some driving times. Since the mountains are involved, I don't think trains times will get much better and the relative distance analysis can be done this way for the part.

Interlaken - Zurich 1:30
Interlaken - Munich 4:30
Interlaken - Berlin 9:15
Interlaken - Vienna 8:40
Interlaken - Innsbruck 4:30
Interlaken - Salzburg 6:00

So Zurich is the closest but probably the least interesting of the three. It would make a good airport to fly in or out of because you can leverage your Interlaken stay off of it.

Berlin and Vienna, while fascinating will cost you a lot of travel time.

Innsbruck is an option if you want to add some Austria after Munich, but again, not that interesting a city. You would have the chance to see the Alps going through Innsbruck, however. Salzburg is well worth it and if you don't mind a little backtracking Munich - Salzburg - Interlaken would work.

That brings me to my recommendation for you to consider, if you can fly into Munich and out of Zurich;

Munich - train to Salzburg (immediately or see Munich first). About 1:15 by train. Day trip or stay a couple nights
Salzburg to Munich (visit if you did not stop here first) to Lindau - 02:41 by train (visit Lindau, or Meersburg by bus)
Lindau - Interlaken About 4:03 by train

The north cost of Lake Konstanz, or the "Bodensee", is gorgeous and Lindau and Meersburg are gems. In May, the island of Mainau (Google them all if you aren't familiar), just off from Meersburg would be spectacular with it's flowering vegetation.

This is a little aggressive, with 4 possible stops in 10 days. If anything has to go because of your preferences, you could turn Salzburg into a day trip from Munich. You would get

German/Bavarian Gemutlichkeit - Munich
Austrian Culture ad Mountain Splendor - Salzburg
Germany's balmiest climate and gardens - Lindau and Meersburg
Swiss Alpine Magnificence - Interlaken