For a time, my 3-year-old was ADDICTED to Max & Ruby - now that he's seen just about every episode about 946 times, he's moving on. They're perfectly harmless shows - although I do question how a brother and sister bunny, obviously children, manage to have their own house, never go to school, and have no parents (excepting wise Grandma bunny, who, oh yeah, doesn't live with them).
And as bratty as Max can be (getting in trouble with little reprecussion), Ruby and her abject bossiness to everyone with whom she comes into contact is just as annoying.