Heading north (walking with traffic) on Sixth Avenue, you'll find a number of outlandish shoe stores, however the real place to look is on Eighth Street between Fifth and Sixth Avenues.
Along with Skechers (55 W. 8th Street), Vans and other shoes for people being active or just looking that way, you'll find shoes (and boots) meant for strippers, drag queens and yes, plain old you.
Men's and women's, all varieties and colors and sizes. Brand names and knock offs. Cheap, expensive and everything in between.
Watch for Wheels of London (55 E. 8th Street), Make 10 (49 W. 8th Street) and Rugged Sole (7 W. 8th Street), in particular.