[krade]

Analytics, AdSense, Doubleclick, Blogger, Google Groups, Google Voice, Picasa, AdMob, Postini, recaptcha, Nest. AdWords was stolen from Overture, after their ridiculous idea of a monthly, flat fee for a keyword failed. Afaik, Gmail is the only successful Google product that wasn't an acquisition.

[saurik]

Oh yeah, duh: I normally lead with AdWords--as that's like their core business ;P--as the guy who founded DoubleClick lives right around here, but I forgot! Yeah: the reality is that Google really doesn't know how to start anything itself.