Here's a list of albums that have increased in score the most over time. I'm sure there are more than this, but I wanted to focus on things with high ratings or radical improvements. These are ranking in order of smallest to largest improvement over time.
Frances the Mute was a formative album for me, and at that age (around 16) a lot or most albums I loved were growers. It took me tens of listens to actually start enjoying it. The first time I just had no idea what the hell was happening. It's now one of my top albums of all time.