Done on cancer cells growing in a petri dish but still pretty interesting. Apparently the most potent ones were: garlic, leek, brussel sprouts, cauliflower, cabbage, onion, radish, kale, green beans.
Referenced journal article:
Antiproliferative and antioxidant activities of common vegetables: A comparative study (Food Chemistry, Volume 112, Issue 2, 15 January 2009, Pages 374-380)
Video of results:
If anyone wants a link to the full article please message me, thanks.