NICOLAS GHESQUIERE for BALENCIAGA Fashionistas are routinely chomping at the bit over the Balenciaga collection. What is the quality that fans find so appealing? "I can't define what I do," Ghesquiere says. "And I don't really want to."     Fall 2003 Collection     Fall 2002 Spring 2002                   Not available                   Barneys Jeffrey Linda Dresner   Kirna Zabete Balenciaga Boutique 542 W. 22nd St., 212-206-0872     From Paris with Love               balenciaga.com