While I'm a fan of reusable bottles made by Sigg, Klean Kanteen, and Nalgene, they all requite two hands to open them, which can be annoying at times. If you can relate, then check out the Intak BPA Free Hydration Bottle with Meter ($11) made by Thermos.
To see how it works
Unlike other water bottles, this one has a pop top. You just lower the metal ring to unlock it, and press the gray triangular button. The clear top pops off but remains attached since it's on a hinge. You can't loosen it — yay! It reveals a small opening that makes it easy to sip out of without pouring water all over your face. Once the top is locked, it's leak proof. I love the slender body that's easy to grip, and it holds 24 ounces of water. There's even a little rotating meter so you can monitor how much water you've had. One of the best features is that the black top unscrews so it's easy to clean the inside of the bottle. It's also dishwasher safe. If you're interested, this Intak bottle comes in green, blue, red, and purple and you can buy one directly from Thermos.