Microwaves
Advantages
Pass through the ionosphere, so are suitable for satellite to Earth transmission.
Can be modified to carry many signals at one time, including data, television pictures and voice messages.
Disadvantages
Absorbed very easily by natural, e.g. rain, and made objects, e.g. concrete. They are also absorbed by living tissue and may cause harm by their cooking effect.
Need special aerials to receive them.
Radio waves
Advantages
Some are reflected off the ionosphere, so can travel around the Earth.
Can carry a message instantaneously over a wide area.
Aerials to receive them are simpler than for microwaves.
Disadvantages
The range of frequencies that can be accessed by existing technology is limited, so there is a lot of competition amongst companies for the use of the frequencies.
Both microwaves and radio waves
Advantages
Wires are not needed as they travel through air, thus, a cheaper form of communication.
Disadvantages
Travel in a straight line, so repeater stations may be needed
Source: HSC Online
Hope that helps.