kale! any kind of kale. red kale, green kale, white russian kale, lacinato kale, i love them all! kale is probably the only food i eat every single day of the year - it's my favourite FOOD, not just my favourite vegetable!
runners up for me are spinach, rainbow chard, turnips, in-season asparagus, cabbage, and romanesco broccoli!
naama - yes, kohlrabi exists in the states! we sell locally grown kohlrabi at the food co-op i work at right here in urbana, illinois!