While I have grown potato onions and spring onions widely at times, the Negi onion is the one that remains outside my kitchen door and never dies off. Happily this year, they self-propagated (perhaps from the east winds swirling around the place), so now I have three pots outside the kitchen door.
After a couple of years of unsuccessfully trying to grow onions from commercial seed, I've gotten on to a heritage seed from way back that gives you prolific onions and so much more...its's really true that the old varieties are the best!