Renegade Craft Fair (Brooklyn): June 14th and 15th at McCarren Park Pool from 11am - 7pm. The RCF has some great DIY crafts -- everything from jewelry to silkscreened posters to clothing.
Hamilton Park Flea Market (Jersey City): June 14th at Hamilton Park. This flea market is less DIY than the RCF but still has some great surprises. Kanibal Home has been attending for the last several years and last year we dragged home everything from vintage cameras to WWII era promotional mailers to handmade jewelry. It's worth the trip to Jersey (come on, the PATH train isn't that scary) and the downtown Grove Street area has some delicious restaurants and unique bars to grab a drink and some grub at before heading home.