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…
Award for most change in the cars visual demeanor for the least amount of actual change has the go to Honda for the S2000. The AP1 and AP2 are near identical yet the AP1 looks like a more refined happy go lucky Del Sol on steroids but the AP2 looks legitimately angry.