L.G.
I have used the Playtex Insulated cups for years. First with my oldest son and now with my younger one. They go in the dishwasher and don't usually leak. They are sold at the grocery store and places like WalMart and Target. I have some that are insulated and some that are not. With milk I prefer the insulated because it stays cold longer. It is just a personal preference. Good luck!