My advice is to stay away from any of the "retro" looking tricycles that are now popular (Radio Flyer, in particular). These are very unstable and built just as cheaply as in the good old days, and my daughter never had any fun on it. Traditional design is not necessarily a bad thing, just make sure it is sensibly designed. My daughter is now four and has her first training wheel bike (a Trek Mystic), which she likes very much, but her absolute favorite is the Adams Trail-a-bike that clips on to daddy's bike - I highly recommend this at age four to five.