Go, Diego Go! 10oz. Insulated Straw Cup

The Munchkin straw sippy cup is easy to clean and fast to re-assemble (as the other reviewer said, it's easy to reassemble if you pop off the straw cover per the included instructions). Some of the Munchkin cups leak around the lid where it screws on if the cup is tipped. I've also seen occasional leaks around the straw.

I also have the Nuby No-Spill Flip-it Straw Sippy Cup. Nuby's website says they are BPA free. The Nuby cup does not leak. However, no re-assembly instructions or tools are included, and you need a tool to reassemble it - something flat and small, to guide the large end of the silicone straw through the flip-it lid. It takes time and patience even when you know how to do it.

Both brands can splatter liquid drops from the straw when the lid is closed & opened. No cup is absolutely leak free. Also, I find that the soft silicone straws with built-in valves wear out quickly and you need frequent replacement straws to really reduce the chance of leaks.

I like the Munchkins for all-around use because they are so much easier to reassemble, but if I need to minimize the chance of leaks then I use the Nuby Flip-it. If your kids are old enough to understand not to tip over a straw cup, you'll save a lot of money on replacement straws if you use cups that have regular straight straws.

By the way, the Dr Brown's natural flow cleaning brushes are great for cleaning straws! However, Munchkin's customer support says not to use a brush through the valve because it can damage the valve. They said to soak in hot water and vinegar after washing to kill bacteria.

NOTE: You must "activate" the valve on the Munchkin cup before using it for the first time or it might be nearly impossible to suck anything through the straw. The instructions are not clear on the best way to do this. Here is what Munchkin customer support told me to do: hold the soft straw under hot soapy water for a couple of minutes while pinching the valve firmly.
I recommend testing it afterwards to make sure you can suck a drink through the straw.Buy Go, Diego Go! 10oz. Insulated Straw Cup!