Circus is really good. It has the technological wizardry of Blackout, but more, ya know, melody.
But as Sam and I discussed at lunch today (because we're gay), "Trouble" is pretty much Madonna's "Get Together" slowed down and with an 8-Bit effect going on (those who use GarageBand will get that reference.) Listen for yourself (and if you go to the YouTube page, look at the comment. I wonder if that's what Britney's Bitch was thinking about as well):