Buying a full set of knives will give you plenty of choice with various sized knives to choose from however I would expect that within each kitchen there are the top two or three knives that get picked up all the time and some of the sizes sit there neglected! I would strongly suggest choosing the knives that suit you; now, for example, this may be just one good all rounder that you will use for most jobs (like a Santoku or a Gyuto) or you may feel that one small, one medium and one larger would be best and if you’re daunted by larger knives then just choose smaller ones that you feel comfortable with. I advise choosing the knives that you personally would use the most. Remember, if you are going to opt for fewer knives this means you could always step up a level in quality and get fewer but better quality knives!