If you havent checked out The Fiery Furnaces yet, you probably should. Not sure if you'll like them, but they're at least worth knowing about. HeartlandGirl and I saw them open for The Shins in May. Their latest album, 'Blueberry Boat' has gotten some majorly good reviews (see Pitchfork). I'm still not sure if I prefer 'Blueberry Boat' or their first album, 'Gallowsbird's Bark', but they're both very good. Their first is a bit more standard songwriting, their most recent has very long songs that pretty much include 3 to 4 songs/melodies in each. Very interesting stuff.
I'll agree with HeartlandGirl about BT along the electronic music lines, and I'll also recommend DJ Tiesto (I'm sure she will too). I've really been digging him lately.
I also better agree about Placebo, or I'll get in major trouble.

Seriously though, their most recent album 'Sleeping With Ghosts' was amazing. The Greatest Hits CD should be a good bet too.
Here are some other bands/albums I've been digging lately that I think you may like:
Dismemberment Plan - 'Emergency & I' & 'Change'
Cursive - 'The Ugly Organ'
Cooper Temple Clause - 'Kick Up the Fire, And Let the Flames Break Loose'
Bjork - 'Greatest Hits' & 'Medulla'
The Cure - 'The Cure' & 'Disintegration'
Beta Band - 'Heroes to Zeroes'
M83 - 'Dead Cities, Red Seas, & Lost Ghosts'