Google Play
Biggest Market (1.5 million apps!)
Yandex
%10 discount(credit back)
Samsung Apps
Market for Samsung devices
F-Droid
(Free and Open Source Software) applications
Mobiles24
7000 Games 6000 Apps
Appslib
38.771 apps available
Mikandi
Adult App Market (18+)
Clean App Network
Very few but quality apps
Local App Markets
Appsss.Net
Turkish- Türkçe Market
T-AppMarket
Turkish- Türkçe Market (Turkcell)
Redirects to Google Play
Solutions for who want to have  his own App Markets.
These are the old markets which are not working right now:
Handster
Becomes Opera App Store

-AndroidGear   -Applanet – Androitpit

-Appoke        -BlapkMarket  -Handango

-NetDragon    -Appstoreconnect -GoApk

-Mobihand    -Me and My Droid