Adwords made it clear long ago that the use of superlatives such as "best" were not allowed in their ads. But I've never read anything about use of superlatives in title tags influencing organic rank in SERPs.
Over the last two or three years, I've used words like "best" in the title tag of certain pages, since some people apparently include that word in their searches ("best widget company," etc).
Within the last year, I've noticed pages like that dropped at least slightly in the SERPs. Since then, the majority of first-page results including words like "best" tend to be directories or blog posts ("The 15 best widget sites") as opposed to actual business websites.
Is there any evidence that Google will penalize a business website in its organic results if superlatives are included in the title tag? Or are the drop in rankings that I've noticed simply a coincidence, a result of Penguin playing favorites with directories and non-commercial "authority" sites?