I've got CK EU2 and Vicky and they're all really excellent games. I think I prefer Vicky to the other two and EU2 to CK, but the detail and at the same time grand scale of them is incredible.

At the moment I'm playing a grand campaign starting in CK as the Duchy of Gwynedd and, using the save game conversion tools, I'm going to play through into EU2 and Vicky. 1066-1920. I'm in the 1320s at present so I've still got AGES to go yet.....