Question has been asked tons of times, answered more than that. To go through it again, try Money Bookers and E-gold. They are the most popular ones. 2 CO is good, but charges that initial fee of $49..
Depends on where you are I would think. I am in the United States and I use a merchant account through Cardservice International and LinkPoint as my gateway. I use LinkShield to help detect fraud since it uses the First Data platform and that platform is able to collect data on transactions from LinkPoint, Verisign, and Authorize.net gateways