You can never have enough. Fuji, Sony, JVC, Panasonic, TDK are all equal in quality and performance. So with that in mind, look for the best price. I've read from several sites that mixing brands is a no-no. Different brands use their own tape lubricant formula so that mixing brands will leave residue on the tape head. I had to learn it for myself. Well, they were right!!! After several hours of taping, mixing Sony and JVC tapes, horizontal bands, and spots, began to appear on the recorded video. From this experience, I will have to recommend that you stick to one brand.
Whatever you record on a tape, write the date and a description of what is on that tape, and save it! Something you may have recorded on that tape could be priceless.
A good tape head cleaner is another accessory to add.