We are a family of four, and I recently came across a set of stainless steel cups at REI that were perfect for us! I got them on clearance for around $20. They just so happen to come in our four favorite colors, so we quickly assigned a colored cup to each person in the family. These cups now stay in our travel trailer and we use them while camping. They are great!

Colorful, so everyone knows who's cup is who's, they are stainless steel, easy to clean, and keep your drink cold. Two thumbs up for these great cups that are perfect for a family of four! Two thumbs up. I highly recommend them for other families looking for a good set of cups for camping.

These cups are the GSI Outdoors Stainless Steel Cup Set. We love 'em!

My favorite color is orange, by the way, so you know what color cup is mine! Here's a picture of mine below, with my smoothie and matching orange paper straw.