Risa

She starts off pretty acerbic with a clear bias toward Data, but they were definitely going for a character arc with her and she started having some character growth as the season went on. She later encourages and supports Data when he's having a mini crisis about losing at stratagema, and she takes an innoculant so she can drink the poisonous tea Worf offers her. Then they brought back Bev and we never got to see it really pay off. Then for ages Crusher is barely anything more than set dressing and a 'will they won't they' relationship for Picard. I always thought Pulaski was a more interesting character than Crusher and the show would have been better for keeping her.