Sounds like you are looking for ornamental alliums. I don't grow many of those, mostly the edible ones, but you could start with Google and go through Wikipedia, and follow the links. What is available to you will in part depend on your climate; so find your climate zone, too.

I only grow edible alliums to but I DO see the ornamentals around public and rub the leaves to check the smell... I even seen them from conpanies, when looking for edible garlic bulbs on the internet... I cant recommended them because, even though I haven't had any problems ordering from them, I know that people have.

I love the ornamental alliums. I'm a novice. I was thrilled to buy25 bulbs at WalMart and plant them last fall and they came up this spring in a wonderful dazzle of Purple Sensation. In the past I had many Drumstick and 5 little blue Drumstick, but none of those have come up for 2 years. I love Christophi also. I don't like paying big bucks so I enjoy what I have. I have allium nigrum that blooms in the fall--white flat heads of tiny white blooms. Look great in the autumn. Some day I'll be rich and get a Giganteum, but for now I just enjoy the regulars. I told my neighbor they were ornamental onion/garlic and she wanted to eat them. How rude! (just kidding). I love the FLOWER part! Grow them with something that contrasts in color.

Heidi in Nebraska

I think the blue ones are stunning... I think the flowers on elephant garlic are nice too.. The ones I see planted at parks have leaves like garlic chives but the flowers look totally different.