2 examples come to mind.
The first track I ever heard on the radio by them was Rock 'n Roll Star and I fucking HATED the way he was pronouncing "sunshine".
Few years later they were my favorite band.
Second one is The Smiths/Morrissey.
I thought his voice was absolutely terrible like he had a hot potato in his throat but years went on and I began absolutely loving it.
Anyone else change their mind completely about some music?