I like 'faucets' that have game elements inside, something like robotcoingame, just that the intervals are too short, and probably better game elements inside like 'leveling up'. Some of the bitcoin games outside are nice, and I am using cannonsatoshi, and it makes me spend lots of time on it to continue my earnings, and the best is that there are no captcha, which makes it even better.
Add bonus rewards to your faucet to make it even more attractive and special, so that users would come back for the next claim. It isn't easy creating a good faucet that everyone likes and profit from it, but I would like to see one of such kind!
Good luck for your project!