Some recreational vehicles do not come with portable generators. This is because the vehicle manufacturer wants to save money and offer a lower price. Many fifth wheel wagons have no generators on them. If you own a 5-wheel trailer, you can either buy a silent generator. There are many good manufacturers of quite generators like Honda, Onan and Coleman.
The question is which is the very best generator for you? Well first you have to decide how much energy you need to generate. If you are going to be in warmer climates, you need a generator that can run an air conditioner and that means you need more power and sometimes up to 15 amps just to run the air. If you have a microwave, run a laptop and a TV, chances are you'll need another 20 amps or 35 amps in total.
A 35 amp generator is a fairly large generator, as well as expensive and if you can manage with less then maybe you might be looking at other options. This means that you cannot run everything in your recreational vehicle at the same time, but you will be able to run all different items individually.
If you can get with a 2000 W Honda 98 CC generator then you can choose one up to about $ 1000 or be used for about $ 250 on eBay. They weigh about 50 pounds and are perfect for a five-wheeled car. A 3000 W Honda generator with 196 cc or 6.5 hp will drive you almost $ 1800, but they are very good generators.
Onan generators are comparable in cost to the amount of energy production. Coleman manufactures an 1850 W sports generator that puts out 15 amps and costs just about $ 500, but it's a bit more noisy and you may not like it, but people who own them say they work well. Think of all this in 2006.