Kitchen knives are very personal. I think that choosing one requires attention to three things: the steel, the architecture, and the aesthetics. The steel is most important. Soft steel kives, like the carbon steel ones prevalent before 1960, are easy to sharpen and can maintain their sharpness if you use a steel on them before every use. But they stain easily, react to acid and eggs, and sometimes discolor foods, like onions. The harder the knife, the harder it is to sharpen and the less good a steel does to keep them keen. High carbon stainless is the reasonable middle ground between straight carbon steel and the really hard alloyed steels. Architecture is next. A knife has to be designed to do a job. The two best shapes are the common chef's knife with the (generally)triangular blade, curved gently along the cutting edge, and the Chinese knife (commonly misnamed a cleaver). It has a rectangular blade, not very thick, also curved gently along the cutting edge. Generally it's about eight inches long and can vary in width from one to almost four inches. A number two knife, about seven by two inches, is ideal for me. Aesthetics is the least significant concern, but weighs heavily with the public relations and advertising departments of the big producers like Henckels, Wusthof, Forschner, and Sabatier. They sell looks, especially in beautifully matched sets, and they charge outrageous prices for beauty. I don't buy knives these days; my main three are very old, and all have carbon steel blades stained to a blue-grey-brown camouflage patina. They comprise an eight inch chef's knife (of no brand I remember) bought at a knife shop in Thiers, the knife forging center of France; a ten inch slicer I bought at a yard sale in Kansas City, and an old Lamson and Goodnow four-inch utility /paring knife that I bought thirty years ago in New York. I had a great Chinese number two knife I got for a couple of bucks in San Francisco's Chinatown twenty or so years ago, also carbon steel, but I left it by accident in an apartment I rented in Paris a while back. I took it with me because I regarded it as my most indispensable knife, with which I could do almost any kitchen chore, from dicing onions to boning chicken. I have other knives, more expensive and more beautiful, from the big German and Swiss and French producers, gifts, mainly. But I don't use them much, except when I have to cut acid foods I don't want to discolor.
