Were on the QE2 last year and went to Oslo, Stavanger, Bergen and Geiranger so can give you some info on all of those - if any apply.
You can email me directly on email@example.com
Just briefly -
Oslo - way too much to do in one day so you need to be selective
Geiranger - the only place we took a tour - superb
Bergen and Stavange - easily explored by yourselves. Bergen is large, Stavanager you may want to branch out a little.
Depends also on what you like to do.
If I cna I will gladly help.