What is best is relative. Everyone has different needs. Similarly, everyone has different printing and scanning needs.
If your printing needs far exceed your needs for scanning, it is a good idea to invest in a printer. Make sure that the printer is capable of handling heavy tasks. There are printers in the market that offer greater paper handling flexibility with the use of extra paper trays. Aside from the capacity, be sure to invest in a printer that is capable of printing at high speeds. A minimum of 30 pages per minute should be enough. While you’re at it, go for laser printers. They offer superior quality and cheaper printing cost per page compared to inkjet printers. This would make a reasonable choice if you were into mass-producing booklets, flyers or brochures.
In the same way, if your scanning needs are greater than your printing needs, then go for a dedicated scanner. Modern dedicated scanners are capable of scanning resolutions as high as 4800 x 9600 dots per inch. With this resolution, you can make sure that the quality of the pictures you are scanning is preserved. This only applies to scanning pictures. If you are into scanning a lot of documents, go for the scanner that has an automatic document feeder with high capacity. This way, it will be more convenient since you don’t have to feed the pages individually.
Both options above are applicable for offices especially if they are into the business of printing or scanning. However, if your business involves a lot of simultaneous printing and scanning, you should invest in both devices. Get a great printer as well as a great scanner.
However, if all you want is a home printer, then you should take advantage of multifunctional printers. Buying a small printer scanner is much cheaper than buying a printer and a scanner. In addition, you get to save space since you only have to allocate space for one device.
Modern multi-functional printers already offer high-resolution printing as well as high resolution scanning. Take for example Canon’s Pixma MX330. In color, it prints at a speed of 4.5 images per minute at a resolution of 4800 x 1200 dots per inch. It has an optical scanning resolution of 1200 x 2400 dpi. These figures should be enough for you to provide decent, if not high quality prints, as well as acceptable images. If having these printing and scanning results are enough for you, then a small printer scanner is all you need and not a high-speed printer or scanner.
Unless your business revolves around printing or scanning, the best option for you is a combination of both. Get a multifunctional printer.
