Most of these faucets aren't worth it. They give you miniscule amounts of money, often only in the magnitude of 0.1 to 1 cent per hour.
Airdrops are another story. There's not really a "Best" one, as you won't know it's the best one, until it's too late and the airdrop has stopped already.
Some sites allow you to register on them and claim a certain amount of tokens/altcoins, which are often worthless, but if the project is successful, it might be worth more than just a couple cents.
wcex.io is the only example I can think of currently, that's still active. I'm not really in the airdrop business though, so there must be far more Coinstarter.com and authorship gave away tokens a couple weeks ago too.
I recommend you to join Bounty Campaigns. Instead of just claiming your crypto, you must do certain tasks for it.
Translate, Retweet, Post with an advertisement in your signature, Publish articles about the project and much more. They all give a lot of "free" cryptocurrencies.
Summary: Don't do faucets/airdrops. Try Bounty Campaigns. Those reward you far better!