Which Portable Generator Will be perfect?

We know that Portable generator for emergency electricity supply. But have a problem that I can't choose which will be perfect for me? I mean there have many kind of portable generator like diesel generator, gas generator, electric generator, fuel generator etc. All of them which will be suitable?
Please help anybody. I am waiting for replay.
Thanks.

Which appliances do you wish to power? (Example, a refrigerator is needed for medications which must be kept cool.)

Add up all power requirements of appliances you'll want to run. Then purchase a unit rated for at least that much, because if you overburden the unit one time, it may not work right again.

What about the unexpected? Will a neighbor ask you if he can plug in his refrigerator?

You do not necessarily want a larger unit than your needs. A large unit uses more fuel than a small unit.

Do you wish to power the entire house? Does your circuit breaker panel have a transfer switch? This provides a safe hookup for a generator.

Or do you intend to plug all appliances directly into the generator?

You'll need fuel. Which fuel is easy to obtain in your area? Especially if you must drive through snow, storm, etc.?

Are you knowledgeable about engines? Then you might consider buying a used unit.

Do you have a vehicle with power take-off? Then you might only need the electrical half of a generator.