The type of CNC machine that would be best for producing sensitive, complex parts in manufacturing would depend on the specific requirements of the parts, such as size, material, and precision. However, some options that may be suitable for producing sensitive, complex parts include:

1. 5-axis CNC machines: These machines have five axes of motion, allowing for complex and precise machining of parts with multiple faces and angles. They are suitable for producing complex parts such as aerospace and medical components.
2. Micro CNC machines: These machines are designed for precision machining of small parts and are ideal for producing micro-components such as medical devices, electronics, and jewelry.
3. Multi-tasking machines: These machines are able to perform multiple operations such as turning, milling, and grinding on a single machine, which can be useful for producing complex parts with multiple features.
4. EDM (Electro-discharge machining) machines: These machines use a process called electrical discharge machining which is suitable for producing complex geometries and small features. They are mostly used for high precision parts and hard materials.
5. Laser machines: These machines use a laser beam to cut and machine materials, which can be useful for producing delicate, complex parts with high precision.

It’s important to consult with a CNC machine expert or vendor to determine which type of machine would be best for your specific application. They can help you evaluate the specific needs of your manufacturing process and recommend the most appropriate machine to meet those needs.