We will have a car for our travel in early June. What do you recommend as the best Gondola ride and must-see mountain vistas in Southern Germany or border towns of Austria and Switzerland?

Garmisch-Partenkirchen: take the ride up to the top of the Zugspitze. Wonderful views on a clear day.

I'll second that. We also did a wonderful little trip up a lift and a nice hike down the Wank (yep, that's what it's called).

Both the Eagle's Nest and the other mountain (Jenner?) are scenic at Berchtesgaden, but nothing like the Zugspitze.

At Lake Walchensee, there is a cable car up to Herzogstand, which has beautiful views down to the lake and a wonderful old lodge there, where we had the most amazing apple streudel ever!!

Try the gondola ride up to the Untersberg overlooking Salzburg and Berchtesgaden.This ride is not for the faint at heart. It's quite steep but the views are worth it! The top of the Untersberg is long and flat and there are numerous hiking trails that can be accessed at the top. These would be day hikes for experienced hikers. There's also a nice mountain "hutte" up top with food and drinks.
You can access this ride in the town of St. Leonhart just outside of Salzburg and Berchtesgaden.
There is also a two person enclosed chair lift that can be accessed at the base of the Jenner at the Konigsee. This is a very scenic ride with great vistas of the high alpine areas.

How about hanggliding and parasailing near Schwangau? It's a real trip.

Oh, Patrick, please do tell us more about the significance of the term "wank" since you obviously want to.....sounds like a great topic of discussion for the next GTG!!!