The Villa Monastero in Varenna, set along the shores of Lake Como. Unforgettable.

Giverny

NY and Brooklyn Botanical Gardens

Guy18: another vote for Bodnant...also the gardens at Port Meiron in Wales, surrounded by the Italianate village.

Villa Carlotta on Lake Como at the Bellagio Ferry pier.

And another vote for Taranto on Lake Maggiore.
The Rose Gardens in Tyler, Texas are worth mentioning...as is the entire city of Kyoto and it's numerous Japanese gardens, small and large...made an indelible impression 60 years ago on a 17 year old GI who is now an old man, with a sharp memory of such things still in tact.

Stu T.

Brookgreen Gardens near Myrtle Beach, South Carolina, USA
Last week of March or first week of April, when azaleas and dogwood are in bloom.
very beautiful. Lots of sculpture pieces done by a woman in the early 1900's.