I'm a life-long sufferer of chapped lips, so I have been through a ton of balms, softeners, chapsticks, and the like. One thing I've discovered is that natural ingredients work better than petroleum-based stuff and a great balm needs two ingredients to combat even the most chapped lips: shea butter and beeswax. Not alone, but in combination. This is the only constant in the best products. Other ingredients to look out for are Vitamin E and natural oils (soybean, coconut, etc.).
My current favorite balm includes all of these: BlueQ's Get Real line. As it says on the package: No Fake Crap. It soothes even painfully cracked lips and keeps my lips supple for hours. I like that the flavoring is subtle so I don't keep licking my lips. You can wear it alone or under lipstick and it still works. I never go anywhere without a stick of Get Real in my bag.
Find it at BlueQ.com for only $3.99.