Alliums are such fun flowers. I hereby resolve to plant more of them.
You're familiar with chive flowers, of course:
They make a great garnish.
The larger decorative alliums make lovely fireworks bursts of white or purple in your garden.
And even after they go to seed they have an interesting shape.
A couple of years ago I planted seeds for bunching onions, which I got from Kenny at Veggie Gardening Tips. They didn't sprout until this year! But now that they're established, I expect them to stick around.
I originally thought they were Egyptian walking onions, which grow their bulbs on the top. The weight bends the stems over until the bulbs hit the ground and take root, hence the "walking."
If the bunching onions were just for kitchen use, I would mound the dirt up so the stems are blanched. But I enjoy them as much for their looks as for cooking.