This is crazy. After three kids, we've collected a good amount of sippy cups. I have found brands I prefer as well as brands that ALWAYS leak!
So, I got down the box where I stash spare cups and sorted them out. There were bonus snack cups, too. I kept three snack cups, got rid of the sippies with valves I hated, bottles I haven't *ever* used, etc. I still had a few left, but I'm okay with that, for now.
Off to Goodwill!