Websites like TopGameserver.com or Top100Arena have dedicated sections for Ikariam . These are ranked by votes.
Some private servers advertise as "100% free." After you spend three weeks building your empire, the admin announces a "Donation Drive for Server Costs." Suddenly, the player who donated $20 has a maxed-out fortress and 1,000 Steam Giants. You are back to square one. ikariam private server link
Before joining a private server, keep the following in mind: Websites like TopGameserver