Wauwatosa vs. Greendale   Year Founded: 1892 Population: 46,396 Scouting report: Wauwatosa's Village and East Tosa districts offer an eclectic array of small shops and eateries. It is home to Mayfair, the mall that draws stores found nowhere else in Wisconsin. There's plenty of outdoor recreation: splash in the Tosa Pool at Hoyt Park, walk among butterflies at the Monarch Trail, bike the Oak Leaf Trail or Menomonee River Parkway or play at the newly developed Hartung and Hart city parks.   Year Founded: 1936 Population: 14,046 Scouting report: Greendale's village center, listed on the national and state Register of Historic Places, helps give it its small-town charm. It is home to Southridge, Trimborn Farm - a Civil War farmstead - and the Oak Leaf Trail traverses though it.