you've strategically hit upon the logo & icon portfolio and blog of UK logo designer Graham Smith — the original Logo Smith since '86.

Coca-Cola vs. Pepsi Logos – Revised Edition is a side-by-side comparison of all the various logo designs used by Pepsi and Coca-Cola through out their hugely successful run in business..
Read more http://www.underconsideration.com
Hat tip to Brand New for putting this altogether. Once you see all the Coca-Cola logo variations up together you realise how many there has been. It’s a little surprising as I have always viewed the original script version as being their only brand logo, or more accurately the logo I best associate with Coca-Cola. The latest version from 2009 is the cleanest and purest of their logo styles.
I would say that Pepsi has had 3 major type logo style changes: the original script style covering 1898 to 1950 which saw the introduction of the bottle top design, the sans-serif style from 1961 through to 2005 with the last major type style change in 2008.
My favorite Pepsi logo was the bottle top style of the 1973 version.

Brand Reversions of Pepsi and Coke

Coca-Cola-Pepsi Brand Reversion

Pepsi-Coca-Cola Brand Reversion

coke 1940 and 2008 looks exactly identical. the more things change the more they stay the same.
Personally, purely from an aesthetic pov – I like the NEW pepsi logo and the OLD coke logo. I’m not a fan of the new coca-cola logo treatment.
Ditto to ’73. It was so simple (ahhh…in a simpler time–was I alive? No. But that’s what I hear.) Hate the new logo.
The Coca Cola logo is a true example of how evolution is more advantageous over revolution. If you asked the public they would say the coca cola logo has hardly changed over time. By constantly tweaking/ cleaning up their logo they have managed to keep public recognition high. Coke as a brand know who they want to be where as Pepsi are constantly trying to take PR / interest off Coke without concentrating on their core brand values to build their market presence.