We use AuthNet, but are in the process of migrating to Braintree.

Two reasons:

1. The AuthNet API is old and crusty, and their support is miserable. The Braintree API is beautifully designed and they provide wrappers written in Python (we're a Python shop), Ruby, PHP, etc. Their support is awesome too: the first time I ever emailed them, I got a near immediate response that was footnoted/supported with links to their docs.

2. It's a pain to migrate, and not sure when we would have done it, but the catalyst: AuthNet only settles transactions in USD. We've taken our business international and Braintree settles in 20+ currencies.

Of all the third parties I interface with as an engineer, Braintree has been my favorite.

Source: https://www.quora.com/How-does-Uber-handle-payments

Perfect Money/Payeer/Epay/Neteller: www.ituglobalfx.com.ng