The one you have faith in. Really. It's that simple. Of all the calls on the market, hand and Ecalls alike, they all will work sometimes, but if you don't have confidence in the sounds the call is making, you'll be more likely to get sloppy in stand selection and you probably won't stay attentive for incoming predators, and will probably quit a stand too soon.
SO, use what gives you the most confidence. I've said it 100 times but I'll say it again, cottontail distress calls more predators every year than all the other sounds combined.