There's been a pretty impressive spike in airdrop activity this week. Only drawback is that you have to constantly be checking the forum as most of them are time/participant # limited so you have to get on them quick to get anything worthwhile out of it.

eBTC just ended, but is a good example of that

Some that are still ongoing are

PoSToken
Funnel Token
Texcoin
Spectre.ac

Also Ethereum Dark is a pretty good project that will be starting a third airdrop potentially soon.