Wifi Printers:

• One printer is enough for many people
• Only need a power cable
• Can be placed anywhere within range of the wireless signal
• Users can print from anywhere within range of wireless signal
• It is cheap, especially considering one printer is enough for many computers
• Easy to set up

USB/Parallel Printers

• One printer to one Computer unless you configure computer to share the printer
• Needs power cable as well as a USB or Parallel cable connecting to the computer
• Needs to be placed very close to the computer
• Can only print from the computer connected to it
• Cheap
• Easiest to set up

Network Printer Using Ethernet

• One printer is enough for many people
• Needs power cable as well as Ethernet cable, generally has highest power consumption
• If you want to place it far from a router or switch it may involve putting cable through walls or floors
• Users can print from anywhere as long as they are connected to the same network as the printer
• Expensive
• More difficult to set up

As you can see by this comparison Wifi Printers are usually the best choice for a home or small business.