evolution/intelligent design
The blog Neatorama had an interesting post last week showing the evolution of some tech company logos. I don't offer these necessarily as commentary on good logos (all the ones included in their post), though I would say that the logos above are strong ones that have no reason to be changed. (I dread the day when I have to write a post chastising IBM for dropping their legendary current logo for some shiny 3D thing... not that I have any reason to think they are, but the way things are going anymore...) I'll admit that I've never loved the Google logo - but it has such strength based on its recognition that it shouldn't be touched (outside of the Google Doodles that the logo is known for). There are times when brands that may not have the best design have such history, cache, or familiarity that those factors trump a change for the sake of 'good design.' The post also includes some interesting anecdotes about how some logos originated or evolved over time.