Some currently active airdrop update 11 Jan:

Suchapp: http://vy.tc/eYNGc13 - very interesting airdrop campaign and solid project => definitely should keep an eye on 2018
Dividend https://www.dividend.cloud/airdrop.php
IOST Link
KMC: Telegram
OLXA: Link OLXA
Zeepin: https://www.zeepin.io/bounty/?r=MvB7P
Benebit: Link form
Polymath: https://polymath.network/
ConnectX: Link ConnectX
Upcoin: https://upcoin.com/
TIM: http://www.talking.im/airdrop/hsMsAobiqM

Follow the links to earn free coin of each project. Good luck to you all!