It's been 6 months or so since I was at the Derby but It's very likely Nolet's. Nolet's is a great gin for people who don't think they like gin (and everyone else too). It's a Holland style gin, so it does not have the strong pine, juniper, notes that a London style gin will have. A very soft, easy gin with strong fruit and floral flavors. It's a great choice for gin based tropical cocktails or a Singapore Sling. Another popular choice along this easier drinking style of gin would be Hendrick's. Hendrick's is a Scottish gin with a hint of cucumber.
Almost as important as the gin is your choice of Vermouth. Look for Noilly Prat Extra Dry (pronounced nwa-yee Praht) at about $15 a bottle or better (more expensive). The Noilly is just a great all around vermouth and the 'better' stuff is more for hipster cred.