I am trying to compare and contrast different aspects of Hamlet with parallels found in Romeo and Juliet, A Midsummer Night's Dream, Twelfth Night, and Henry IV Part One.
One way to compare and contrast these plays is to analyze common Shakespearean themes. For example, one common theme in many Shakespearean plays is mortality. Hamlet, himself, is obsessed with thoughts of death and mortality. The whole "to be or not to be" speech (III. i. 56-88) is an expression of Hamlet's existential thoughts regarding life and death. At first reading, it appears that Hamlet is comparing whether life or death is preferable. But I think what he really is saying is that life and death are one and the same. Death is a part of life. After all, we all eventually die, right? Grammatically, "to be" is a passive verb. I believe that Shakespeare intentionally used the passive tense of the verb because he wanted to portray that Hamlet feels living and dying are passive activities. Another quote from that speech, "to sleep, perchance to dream," demonstrates that Hamlet considers death nothing more than sleep. Later in this speech Hamlet says, "the undiscovered country, from whose bourn no traveller returns." "Bourn" means boundary, so Hamlet is saying that death is like going to the border of a new country, and never returning home again. This tells us that Hamlet understands the permanence of death ("never returning"), but he seems to view it as an explorer's adventure rather than something to be feared.
In contrast to Hamlet's passive view of mortality, death in "Romeo and Juliet" is always linked to passion and often to violence. Romeo and Juliet are willing to accept death rather than be separated from their lover. When Romeo is banished from Verona and may never again see Juliet, he pulls out a knife and threatens to kill himself. (III. Iii) Rather than marry Paris, Juliet ...
This is a very in-depth answer which compares and contrasts themes and symbolism in several of Shakespeare's plays including "Romeo and Juliet", "Twelfth Night", "Hamlet", "A Midsummer's Night's Dream" and "Henry IV part one".