[insidious]

Bings been getting better over the years, and they woo users with their pretty neat homepage of great photos, but it doesn't compare to Google's years of research and innovation on their 'secret' algorithms.
Penguin/Panda updates are always a pain with Google if you're a webmaster, but hell, those quality updates are what makes google so great.

So yeh I use Google. Nothing else really comes close imo.