what contrasts are brought out between the characters of hamlet and laertes?

The largest contrast between these two characters can be found in their decisiveness. Laertes wants to travel to France, and he doesn't stop badgering his father until he gets his way. He knew what he wanted, and he didn't give up until he got it.

Hamlet, on the other hand, wishes to be anywhere but court. He wants to go back to school, and he certainly has no wish to be in such close quarters with his mother and her new husband (his uncle). None-the-less, he buckles and stays because they tell him to.