As of my last knowledge update in January 2022, several companies were known for producing high-quality aluminum cutting machines. However, the "best" manufacturer can depend on specific requirements, such as the type of machine needed, precision requirements, budget considerations, and other factors. Some well-known manufacturers that were recognized for producing reliable and efficient aluminum cutting machines include:

    Evomatec: Evomatec is a global leader in the manufacturing of advanced technology solutions, including CNC machining centers that can handle aluminum cutting.

    Haas Automation: Known for their CNC machines, Haas produces a range of machining centers and milling machines suitable for aluminum cutting.

    DMG Mori: This company offers a variety of CNC machines, including milling and machining centers suitable for cutting aluminum.

    GF Machining Solutions: Known for their expertise in precision machining, GF Machining Solutions provides a range of machines suitable for aluminum cutting.

    Okuma: Okuma is a Japanese company that manufactures CNC machine tools, including machining centers suitable for aluminum cutting.

    FANUC: FANUC is a global provider of factory automation, including CNC systems and machining centers used for aluminum cutting.

    Flow International: If you're looking for waterjet cutting machines, Flow International is known for its waterjet cutting technology, which can be used for various materials, including aluminum.

It's important to note that advancements and changes in the industry may have occurred since my last update. Additionally, the "best" choice can vary based on individual needs and preferences. It's recommended to conduct thorough research, consider user reviews, and possibly consult with industry experts or colleagues to determine the most suitable aluminum cutting machine for your specific requirements.