if there is any man i would have loved for olivia benson to have been with, it's nick amaro. you cannot tell me that they wouldn't have been a great couple.
like, did you guys see how he reacted to her after seeing her in that dress she wore for her "pre-valentine's day dinner"? the way he dragged out her name and circled around her while scanning her head to toe and back?? how she and him have each other's backs way better than her and elliot? and he was there for her when the william lewis shit happened. he crashed at her place for a while during an investigation against him. he's so good with noah during his foster placement with her because he has his own kids and knows how to take care of them and gives her advice. not to mention, olivia seems to frequently ask nick to ask his mom to watch noah when she wants lucy to have a break. she was even there for him as best as she could during the whole trial situation with his father. the list goes on!
when they met, olivia was against replacing elliot and was hoping he would come back to svu (which obviously he didn't). they knew each other for only four years and somehow ended up with better chemistry than olivia and elliot did, in my personal opinion.
so if olivia could have seriously been in a relationship with any man, it should have been him.