However, if you're thinking of other mouse detectives, it's worth noting that Basil isn't the only one. You can also find them in literature:
* The Mouse and the Motorcycle by Beverly Cleary features a tiny detective named Ralph, who investigates mysteries in a motel room.
* The Borrowers by Mary Norton features a family of tiny people who live in the walls of a house. Though not technically detectives, they often have to solve mysteries in order to survive and find their way around the human world.
Ultimately, "great" is subjective, but these are some of the most notable and beloved mouse detectives in fiction.