I really like sweet potato leaves, guava leaves (which I ate in the highlands of Vietnam) and tapioca leaves (often cooked in coconut). All are high in anti-oxidants. I eat these everytime I see them in a vegetable rice stall (not vegetarian)
I also eat bitter gourd/melon-a fruit actually. They are said to be excellent in vitamins (B1, B2, maybe B3, B5, B6 and C) and minerals (zinc, phosphorus, manganese, magnesium and iron). They are said to have twice the highest calcium of plants besides fruit, spinach and twice the potassium of a banana. The carbohydrates are low and the dietary fibre is high. They are said the be good for diabetes and toxaemia because of their phyto chemical compounds (phyto-nutrient, polypeptide-P (insulin-like)) and (hypoglycemic agent called charantin-said to increase glucose uptake and glycogen synthesis in anti-oxidantsthe cells of liver, muscle and adipose tissue). There are a lot of websites with info on the bitter gourd/melon. I am hoping there will be more scientific tests on it. As there are also some toxic concerns, mostly from traditional sources. The exact effects on the liver have not yet been studied. You can check the USDA nutrient constituent values of raw bitter gourd: http://www.nal.usda.gov/ Although its quite bitter I have been eating for the past 15 years.