Hello, can anyone recommend any Arduino-modules

Hello, can anyone recommend any Arduino-modules that are useful?

What is it that you want to do ?

Drive motors - get a motor driver board
Connect to a network - get a network shield
Control a matrix of LEDS - get an LOL shield
Use an LCD screen - get an LCD screen shield
Control external mains devices - get a relay shield
etc
etc

So what is that you want to do ?

Hi, See info on THIS PAGE

and a comparison page HERE