I’ll start with the Porsche 997, the 996 looked alright imo, but it looks “like a 90s Porsche”, the 997 made it look sleeker and more modern. Still looks good today.
As for cars that looked worse after a facelift? Maybe the facelifted 6th gen Camaro? The 6th gen looked great pre-facelift, but they did something weird with the headlights and now it looks so-so…
I was waiting for someone to mention the 4th Gen Firebird refresh. Don’t get me wrong, I like the 93-97. But 98-02 look better to me. So much in fact that I passed on a 97 that had some work done to the LT1 in order to get a bone stock 98 with the LS1. Plus having a blank canvas was higher up on my list of priorities.