Few of the Best markets to publish Android applications are here.
1) Google Play:
It is one of the most popular store for Android apps, all the phones comes with this app pre-installed.
Go to Play store console to sign up & pay 25$ as account creation charges.
Use release keystore to sign the app and upload to store. You have to create Google merchant account to host paid apps. Uploaded apps usually takes 5 to 6 hours to visible in store.
2) Samsung apps store:
This store created and maintained by Samsung & all of its android phone comes with this app default.
Note: All apps goes through testing before they get published, Samsung takes nearly 7 to 10 complete this process, if app is failed in test then you will get mail along with error details. You need to fix it and re-publish.
3) Amazon app store:
This store earlier was restricted to US users only but now its available world wide, creating developer account in amazon store is free. Here you can sell free & paid apps both.
4) Slide me:
This store is maintained by Sony ericsson. Account creation is free in this store, you can upload both free & paid apps here.
5) Appbrain :
It uses playstore apk URL & provides reviews about the apps.