Final answer:
The most distinguishing feature of muscle tissue is contractility, allowing muscles to actively shorten and generate force for movement. Excitability, elasticity, extensibility, and a requirement for ATP are also important properties, but contractility defines their function.
Step-by-step explanation:
The most distinguishing feature of muscle tissue is contractility. This property enables muscle tissue to shorten actively and generate a pulling force, which is crucial for movement. While muscle cells are excitable and respond to stimuli, and possess elasticity and extensibility, it is their ability to contract that most notably sets them apart from other tissue types.
Muscles exhibit excitability, responding to neural stimulation which allows for controlled contraction and relaxation. All muscle tissues require ATP for contraction and rely on the sliding filament model of muscle contraction. However, the contractility characteristic defines their primary function, which is the exertion of force and facilitation of movement. Every muscle's contraction can be conscious (voluntary) or automatic (involuntary), further demonstrating the complexity and critical role of this tissue in various body functions.