Ophelia only has a few scenes in the play, so it is difficult to "get in her head" to see what she desires for herself to any great degree, but from what we see, it easy to recognize that she loves and respects Hamlet, and wants what is best for him.
When we first meet her she has two separate conversations about her relationship with Hamlet, one with her brother Laertes and one with her father. In both instances, she speaks highly of Hamlet and his intentions toward her. Laertes has only her best interests at heart when he warns her that Hamlet may not be able to choose her because he is a prince and therefore, "his will is not his own." Ophelia listens, but doesn't argue. When her father disparages Hamlet's character, suggesting that Hamlet is only using Ophelia and isn't sincere in his affections, she interupts him in at least three places to defend Hamlet's actions towards her. Ophelia is loyal to Hamlet and their relationship.
That said, she does obey her father and end her contact with Hamlet and allow herself to be used in attempting to draw out Hamlet to determine what is wrong with him, but I defend her by thinking that she probably thought she was doing a good thing. If Hamlet has truly gone mad, then maybe she can get to the cause of the madness and help to restore him. A review of her lines in the famous "Get thee to a nunnery scene" reveal this belief. As Hamlet is ranting at her she isn't defending herself, she is praying for Hamlet's sanity/reason to be restored. She says things like, "O, help him, you sweet heavens" and "O, heavenly powers restore him." When Hamlet leaves the scene, her short soliloquy reveals how heartbroken she is that the "noble mind" she once knew is "quite overthrown."
During the play-within-a-play scene she is likely perplexed by Hamlet's bawdy talking to her. She could either be disgusted or amused, but there is no extension of her reaction; so the audience is left to speculate there.
The last times we see Ophelia are in Act 4 when she has lost her mind. The subject of her songs reveal her despair over the loss of her father, killed by the man she loved. She also reveals how upset she is over the end of relationship with Hamlet. In her madness, I am not sure we can suppose what she desires, except perhaps that none of these events would have happened. Her suicide is even left a bit open ended. Did she seek death (desire to die) or did she just let herself drown in her madness?