iHeartRadio- It has custom stations with over 11 million songs while Pandora only has 900,000. Also iHeartRadio's Custom stations do not have advertising where Pandora's does. And you can still get your favorite local radio stations on your phone, iPad, tv, in-dash in your car, Xbox 360 and computer... It's the best. Hands Down.
I love my Pandora as it's very good at picking songs I like, because I've had it so long. HOWEVER, I've been using the new 'custom stations' feature in iheart for a day or so now and it's REALLY good. I still have love for Pandora, but iheart is stealing my heart.