What a botched job they did on Yves Saint Laurent logo. Truly amazing.
I have a soft spot for the original logo, but at 50 years old, it had a good run compared to most brand logo.
Then you have some back-to-beggining like Harley Davidson, which I'm sure YSL would do at some point in the future.
Porsche didn't update their font (or really not much if they did) but they did update the Porsche crest a few times (the one they slap on the hood / rims / keychains / headrest / etc.) though, but to make it better: at every change they actually made the "Porsche" letters on the crest be closer to the original Porsche font (font which was incredibly modern for the time when it came out: I've got a leaflet from a Porsche 356 from 1955 or so and the font hasn't aged at all).