Space Browser Games - Which do you Play and why?

Which games Space Browser Games do you Play and why?

I love to play browser games, especially Space based games. I tested a lot. I already played OGame (www.ogame.org) and Astro Empires (http://www.astroempires.com/).

Currently i'm playing a new game called Orion's Belt (http://www.orionsbelt.eu).

It has several innovations regarding games like Ogame, especially the universe were you can control you fleets like it was an RTS and the battle system (it's not the the same story of the guy with most units win..... tired of those games). Until now it has been very challenging game.