We started using apple juice almost immediately after my daughter was diagnosed, mostly because it's easy to keep around. She's never liked juice of any sort (could never even get her to drink apple before the diabetes), but after she tried those glucose tablets (and gagged) she decided apple juice was pretty good! I've never tried anything else because she hasn't had many lows and they're almost always at school right before lunch. However, she keeps a can of apple juice in her purse, I have one in my purse, we have a stack in the cupboard, a stack in the nurses office at school, and her teacher has one. We also bought frosting in case she was too low for juice, and those are strategically placed as well, though we've never used any of them yet (knock on wood...)
I did find out last week that her daycare started using quesadillas when she's low. Apparently it's worked well and she's been very happy with it, so I guess there are lots of acceptable options.