Nick & Andy are NOT right for each other. They don't have that chemistry that she had with Sam. They hooked up in the first season, then in the second one and the third. There was always something there. She didn't had with Luke or Nick what she had with Sam. So please, bring Andy and Sam back together. They were perfect for each other.
Who's next? She'll be with Epstein, Chris or even Oliver? One at the time until she finishes with the precint.