Murchison Falls is lovely! I couldn't tell you much about the others that you mentioned. But my experience in Murchison Falls was AWESOME! =)
If you want to read more about a lot of these places do visit IN KAMPALA (http://www.inkampala.com/category/travel/). There's information about Murchison, QE2, choosing a tour company and much more.
Kidepo is a long way, but undoubtedly a wilderness experience.
Murchison falls, is very popular. This is an enormous park of 4000 km or so with a lot of wildlife. Of course the falls themselves are a big attraction.
My personal favourite is Queen Elizabeth. I arrived in Uganda as a conservation volunteer, so that is where my heart is ;) I'm just back from a trip in fact. We took the boat trip along the Kazinga channel on Wednesday, and saw 200 African skimmers (rare birds), 30 elephant, a few hundred hippo, 100 or more Buffalo, a wide range of birds, including storks, pelicans and spoonbill; a number of crocodiles and even a leopard, far in the distance. That's pretty rare though - but one of the great things about Safari, every single time is different :)
Have a great trip!