Vienna is a great city - lots of historic buildings and our famous cafes!
I live in Graz which is our second largest city by population. Graz doesn't have the same international atmosphere as Vienna but nevertheless it's a city full of history and bauty. Btw, Arnold Schwarzenegger comes from a small town south of Graz.
I like your username too, there aren't that many people around who have KLM or something Dutch in their username.
I chose mine because I mainly fly KLM as it offers lower fares than OS. I've never flown OS so far, only VO regional jets.
Innsbruck is also a great city. We've got a new regional Airline that flies to Innsbruck with Dornier 328. It's called "Welcome Air" and has a purple and yellow livery. And Tyrolean Airways (VO) which is part of OS is based at Innsbruck. There are many connections to and from Innsbruck. I would recommend coming in summer for sightseeing or in winter for skiing - there are lots of possibilities for skiing around Innsbruck.