It has spawned such classic levels (as I recall) such as Luigi's Circuit, Moo Moo Farm, Frappe's Snowland, Toad's Turnpike, Koopa Troopa Beach, Banshee Highway, Bowser's (infamous) Castle, Wario's Stadium and the ridiculously long and bright track, Rainbow Road, which has spawned at LEAST 5 different versions throughout the series!