Cliffski over at Psotech Games seems to have outdone himself yet again with a superb new offering for his Gratuitous Space Battles game:
I mean, the galactic con quest mechanic has been discussed at length at his blog and, I'll admit, I've always thought it was neat that you'd have an asynchronous Multiplayer element to it (think; Spore, where you pull content form other players into your game passively.) But, just look at this video. Everything is so... shiny!
Highly recommend checking this out, especially if you're not familiar with GSB. To sum it up; it's essentially tower defense as imagined by Admiral Ackbar. You set up a fleet for a given challenge, assign complex orders with differing priorities to effect how the ships behave, then you pull the safety tab and watch everything start blowing itself up. I relented and bought vanilla GSB a while ago, it's definitely unique and worth a try, check out the demo here.