Tom Sawyer was the protagonist in several books: The Adventures of Tom Sawyer, Tom Sawyer Abroad, and Tom Sawyer Detective. You get the idea that Tom was the more "respectable" of the two boys, but appearances can be deceiving.
Tom is tremendously romantic and is pining for adventure. He so wants adventure that he'll create or imagine it if he doesn't get it in the course of his every day life.
Life with Aunt Polly must have been a burdon to Tom. Aunt Polly is a solid, stable woman. No adventure there!
In Huck Finn, we see Tom's inclinations at both the beginning and end of the book. Tom starts his "robber gang", promising actual robbing and hostage taking, and adventures galore. The reality, of course, is quite a bit more sober. The boys run about with nary a burgle to show for their efforts. Tom is quite happy with the gang. His imaginary robber's life is quite full, and he can literally "see" the Spanish Merchants, A-rabs, two hundred elepants and six hundred camels. All the other boys saw was a Sunday-school picnic. But Tom was content with this display of strange visitors!
At the end of the book, it's Tom who engineers the elaborate scheme to free Jim, when all he needed to do was tell everyone that Miss Watson had freed Jim in her will. That would have taken all the fun out of the situation!
Having a Tom as a friend would certainly be exciting, but you'd probably learn to take everything he said with a large grain of salt!