Eh, he did state that the line "I see you." was Hannibal's declaration of love to Will, and I'd argue that being able to wholly see each other is a lot more crucial to romantic love than anything else.

All the murder aside (LOL) I do think Hannibal can love and I think Will is it for him. He clearly shows emotions and care for those he respects or finds interesting, he just views those more as pets or experiments while viewing the rest of the world as livestock. He didn't save Bedelia because he could use her later, he saved her cause he thought she was interesting and wanted to see what she would do, which already put her above the patient who was trying to kill her. Kind of like a fun science project.

The way he's treated Will has from the start been much more a show of devotion than anything. You never see him actually reach out to a "project" and go up to them and seek their attention and mutual appreciation like he does with will, he always just goes with the flow and just kind of comes across them willy nilly, but he actually seeks Will out all the time. Hell, the sole reason he manipulated Abigail into being dependent on him was so that she'd be dependent on him and stay so that Will could play house & live his dream of being a dad.

Sure they might not hold hands and buy each other flowers, but I think if you put them as a team in like, a medical series like ER or something, their behavior towards each other would 100% read as love. It's just that the way Hannibal shows love and dedication is by, you know...manipulating traumatized children and putting sculptures made out of dead bodies symbolizing his love for Will in Italian chapels. Which, you do you boo, I guess.