Boston Celtics. One of the most storied franchises in the National Basketball Association, the Boston Celtics have won the NBA championship 17 times since 1957, more than any other team in the league. The last title came in 2008, after a solid defeat of longtime rivals (the LA Lakers) ended an 18-year championship dry spell. Basketball season runs from late October to April, and playoffs last until mid-June. TD Garden, 100 Legends Way, Old West End, Boston, Massachusetts, 02114. 866/423–5849; www.celtics.com.