Miele W 3123 WPS
The more power per year a device consumes, the less energy efficient it is, making it more costly over time.
Hoover OPH 716DF
Machines which use less water are good for the environment and can save you money in utility bills.
Hotpoint WMFG 8337G
Whirlpool AWE 8840
Front loading machines are good as you can use the space above and sometimes stack a dryer on top. In general front loading machines use less energy, using less water by only partly filling the drum and obtaining higher spin speeds which clean without requiring as much heat.
With a transparent door you can look inside the machine and see what laundry is inside.
The slightly sculptured surface structure of the honeycomb drum creates a thin film of water or air which gently cushions and protects your laundry.
A faster spin speed means you can get things cleaner with a lower temperature of water. Using a fast spin also extracts water, meaning that the clothes come out nearly dry. Generally, anything over 1000 rpm is very good.
With a wider range of programs to choose from you can be more specific and choose the best, most economic program for your needs.
More weight capacity helps if you want to wash something heavy like curtains. A traditional household machine can hold around 6kg, so with a machine much bigger you may waste energy using it when only half full.
With a lower noise level for washing you can worry less about disruption and may be able to do a wash at night or while reading.
During a spin, machines can get quite noisy. With less noise the machine is not as distracting and you won't be restricted to using it at certain times.