There are two types of boning knives: stiff and flexible. The type of boning knife you should use depends on your cooking style.
Use a stiff boning knife for tougher, denser meats like beef or pork. The stiff blade will allow you to use more force, and is safer than a flexible knife when deboning these tougher meats. A flexible boning knife is better suited to thinner and more delicate cuts, and is best used with fish or chicken. The best boning knife is one that is suited to the meat you're de-boning.
Find top-quality boning knives of both styles, from brands such as Global, Shun, Victorinox, Wüsthof, and Zwilling J.A. Henckels. For the best fillet knife options, check out our Fillet Knives section.