I have been with AffiliateFuture.co.uk since 2003 and that makes it 5 years now.
The reason that I sharing about this affiliate program company is because they have been reliable and have so far paid out every commission due. They offer a wide range of companies for you to promote and also various tools and feeds.
They now have US and European operations which means affiliaties from other countries can participate. If you have a UK bank account you can make them transfer your commission straight into your bank account via BACS.