Last year most of my hydrangeas were no-shows (or no-blooms, to put it more accurately). The culprit was a late spring frost which did in any hope of flowers from my mopheads (the H. paniculata ‘Limelights’ were fine).
This year I am overwhelmed with hydrangea blooms. And although I do love my ‘All Summer Beauty’ hydrangeas,

Hydrangea macrophylla ‘All Summer Beauty’ flowers next to variegated Hakone grass foliage in my front yard.
my favorite mophead is Hydrangea macrophylla ‘Blue Danube.’
I probably bought this variety of hydrangea over ten years ago, by order two gallon-sized shrubs from an online source, Wilkerson Gardens, which apparently no longer offers them. Several years later, in a fit of horticultural ingenuity, I read an article on how to grow hydrangeas from rooted cuttings, and voila – I had two more ‘Blues.’ The photo below shows one of them growing next to an ‘Endless Summer’ – if you look carefully you can see the difference in leaf texture as well as in the appearance of the blooms. Although the web descriptions of this shrub describe it as ‘compact’ and good for containers, my experience is that it becomes fairly large (although not as large as ‘Nikko Blue’ or ‘All Summers Beauty.’)

‘Blue Danube’ is on the left (flower buds not fully colored), with ‘All Summer Beauty’ on the right. The latter’s flowerheads have smaller flowers and in my experience are less likely to color pink in my soil.
I think I love this variety so because of the strong purple-blue and purple-pink hues that the flowers have (at least in my garden). ‘All Summer Beauty’ and H. macrophylla ‘Nikko Blue’ have softer blue blooms.
‘Blue Danube’ has colors that can’t be ignored.
That may also explain why it’s my favorite hydrangea for cutting – and for photographing when cut.
If all this has whet your appetite for a ‘Blue Danube’ or two of your own, I’m happy to report that Hydrangeas Plus offers them for sale online.