1) Alternate Launcher with pretty much infinite flexibility on look and feel.
2) Swype like keyboard options. Typing anything on iOS now feels like I travelled back in time to horse-and-buggy era.
3) Tasker app. Enough said.
4) Google Now. Enough said.
5) This is not an app per se, but the "share with" option for pictures etc that simply let me chose any suitable app on the phone that lets me share that particular object using pretty much any means of sharing out there.
And this is not even counting all the hacker'y goodness of having a full root shell with an almost complete debian environment on my Nexus devices. No "jailbreak" required. Nexus devices are rootable by design.
If you call yourself a hacker (this is hacker news... right?) and have turned your nose up at Android so far, you're simply missing out on the future of portable devices. iOS is catered to non-technical consumers and its feature-set (both for users as well as for developers) is accordingly restricted. The future killer apps are being written for Android today and you're not aware of what a mobile device is (and should be) capable of today and by extension, tomorrow.
[Edit: 1, 2 and 3 in that list above are paid apps btw. Checkout out the install numbers for those three on the play-store. Android developers writing stuff for Android (and not just copying stale iOS material) are making plenty of money]