There really isn't such a thing, as it all boils down to preference. Price can be a factor as well. There is no right or wrong species for anyone. If you prefer changing colors every 10 years, oak makes a great species. Oak is very easy to refinish. Maple on the other hand is beautiful naturally and can come with a factory stain. However, maple is very difficult to stain on site. There are many other species, like hickory and cherry, that offer a rustic or sophisticated look. With so many species of wood flooring it basically comes down to what everything comes down to: preference, price and availability.