I hate changing batteries all the time; are any toys better than others in terms of battery life?

You might consider checking out a rechargable or plug-in vibe. The Hitachi Magic Wand is a big, powerful plug-in; the Wahl is slightly smaller, more quiet, and has softer speeds. For a tiny, hand-held toy try the Nea: it's rechargable, silent, very pretty and has a wide variety of vibrations. And if you're looking for a toy to use with or without a partner, the We-vibe is a quiet, multi-fuction toy made of 100% silicone.