Just measured the success of each country using an admittedly rather arbitrary points system of 2 for a winning team and 1 for losing finalists of all the Champions league finals since 2005
Result
Spain 18 points
England 15 points
Italy 7 points tied with
Germany 7 points
France 1 point
So as you suspected Spain are top but only just ahead of England, both have dominated this period in two phases, England the earlier part and Spain the latter, the rest nowhere.
You thought
'Go from 2005 if you want. Spain is the best league. England and Germany compete for second. There is no argument on European results in the CL, EL or combining both.'
I only did the CL but you said there would be no argument in that on its own.