I love the Nuby Sippy Cups, and so does my son.  They are easy to clean, easy to use, and very toddler friendly.  I'm just not sure how to get him to let it go!

The only draw back, the Nuby cups sold at Wal-Mart and a few other chains, are sold without lids.  The only place I can find them is Target, and that's an hour drive for me.