I could sing of my love forever of the Nuk sippy cup from Gerber. It is the only sippy I've found that absolutely DOES NOT LEAK. Period. In the bottom of the diaper bag. Hitting the floor of the restaurant. Being banged nonstop against the coffee table. Being banged nonstop against the table at the restaurant.
I tried every single sippy with Mitchell, and every single one of them leaked, albeit some under extreme toddler conditions. But HELLO, sippies are invented for toddlers, so they should withstand those extreme conditions.
Noah now has all three Nuk patterns - including the red one with the Hawaiian-looking flowers - and I wished they came bigger than just 5 ounces.