‘Rozanne’ has been my favourite ‘blue’ Geranium for several years now. It is a hybrid of G. himalayense and G. wallichianum ‘Buxton’s Variety’ and named after Rozanne Waterer. It was marketed in some places and by some people for some time as Geranium ‘Jolly Bee’ presumably to attempt to bypass the plant breeder’s rights.
There has been a succession of good blue geraniums for me in my time as a landscaper, starting with G. ‘Johnson’s Blue’, G. x magnificum, G. himalayense and not forgetting our wild native G. pratense! Through G.‘Gravetye’, G. Buxton’s variety’, G. ‘Phillipe Vapelle’, G. ‘Spinners’, G. Orion, G. ‘Brookside’, and now G. Rozanne. There were others along the way I’m sure but these are the ones I remember most and these are the main ‘blue’ ones I still grow!
Rozanne
Geranium pratense
Geranium himalyense
Geranium magnificum
Geranium Spinners
Geranium Johnson’s Blue
Geranium Philipe Vappelle
Geranium Orion
Geranium Gravetye
Geranium Buxton’s Blue
Geranium Brookside
english country gardens cumbria 
Beautiful blues indeed. I planted ‘Azure Rush’ this year and am pleased with it.