Concerning Hamlet's love for Ophelia in Shakespeare's Hamlet, any consideration of Hamlet's love for Ophelia is pretty much speculation until Act 5.1 is looked at.
Until Act 5:1, we have the fact that Ophelia thinks Hamlet loves her and that Hamlet gave her a few gifts. Ophelia doesn't understand how much of a windbag her father is, so her judgment is questionable. She also goes along with spying on Hamlet, not out of spite or any questionable motive, but just because. She is naive and innocent.
We learn nothing about Hamlet's feelings for Ophelia from Hamlet, because he is playing a role, acting, every time he interacts with her. Hamlet is cruel to everyone who tries to spy on him, and Ophelia tries to spy on him. She allows herself to be used by Polonius and Claudius, so he uses her, too. That's the cost of betraying Hamlet.
Only when Hamlet has dropped the act of madness can we take what he says concerning Ophelia as accurate. In Act 5.1, after realizing the grave that was being dug is for Ophelia, he says:
I loved Ophelia. Forty thousand brothers
Could not with all their quantity of love
Make up my sum. What wilt thou do for her?
Hamlet declares the kind of love he has for Ophelia: romantic love, not the love that a brother has for a sister. His love is far greater than the love Laertes feels for Ophelia.
Hamlet loves Ophelia with a romantic love, but we don't know this until after Ophelia dies.
Yes, Hamlet loved Ophelia. How he loved her, i.e., what category of love defined his love, is open to speculation. When Laertes and Polonius take Ophelia aside in Act 1, sc. 3, and tell her to beware of Hamlet's affections toward her, they are merely expressing their own narrow-minded views. Laertes tells Ophelia that Hamlet may love her now, which indicates taht Hamlet's affections must ring true even to Laertes. Mostly Laertes warns Ophelia that Hamlet may not have any choice regarding who he marries and that if she continues to let him court her, she may become sullied and then not be considered fit to marry. When, a short time later in the same scene, Polonius talks to Ophelia about Hamlet, he is far less kind. Polonius scoffs at Ophelia's declaration that Hamlet has been gentlemanly toward her and honorable. He tells her she is being naive and stupid. He also reminds her that Hamlet may not be free to choose a wife, but his overriding concern seems to be how a love affair between his daughter and Hamlet might reflect badly on him. Then in Act 2, sc. 1, when Ophelia comes to her father with the news of Hamlet's odd behavior, Polonius immediately surmises that the madness is due to unrequited love. He is sure that Hamlet has been driven to lunacy because Ophelia had been ordered by Polonius to stop seeing Hamlet. If Polonius didn't think that Hamlet truly cared for Ophelia, then he wouldn't have come to that conclusion so quickly. Polonius earnestly pursues that reasoning with the king and queen, too, telling them love for Ophelia was the cause of Hamlet's madness. The reason isn't dismissed by anyone as being implausible which again seems to confirm the idea that Hamlet certainly showed affection toward Ophelia, thus suggesting that he did love her. In the graveyard scene, Act 5, sc. 1, when Hamlet realizes that the funeral he witnesses is Ophelia's, he jumps into her grave and declares his undying love for her. So, yes, I believe Hamlet loved Ophelia.
It is obvious Hamlet loves Ophelia. I bet he thought of her even when he was dying(it probably isn't written because Shakespeare loves mystery and freedom to possibilities by people's immagination). If you carefully observe, Ophelia is such a gentlewoman... She's the perfumed delicate flower Hamlet needed in his 'dying rot world'. She's brilliant, pure, obedient, honest, chaste, crafty, sensible (imagine suffering for death in a warlike state like Elsinore), passionate, strong for being a woman in that times, she's innocent.... She's the little light he needed to feel alive in such a word like the court.... She is a profound message in the book...