I don't think there is such a thing as a "top brand." What you do have are models that are more "popular" than others. And of course, the more built and sold, the higher the odds someone will complain about something in the workmanship.
The best you can do is educate yourself on RV construction, manufacturing, learn about frame, and all the various appliances installed in RV's these days.
Watch lots of YouTube videos, read extensively on forum web sites, and then take that pool of knowledge and begin visiting different RV dealerships and start evaluating the various brands you are considering.
If you REALLY want to see the track history of a specific RV make and model, look at the used units. You will be able to compare with the new units and figure out for yourself what has endured the test of time, and what has failed.
If you want to go one step further, rent an RV for a trip or two and gain first had experience how they really work. This will also help you understand why they are made and designed the way they are, why manufacturers cut corners in some places, and maybe help you identify where something is not right.
Then go visit a few campgrounds and talk to the various campers what they like and don't like about their current camper. You will get a variety of answers on the exact same unit, as everyone's personal likes and dislikes are all different.
There really are no "top brands". There are some brands that have "way over the top" prices! But that does not make them a "top brands" especially if you are looking for some baseline for "quality". That just makes them an overpriced toy.
No one want's to waste their money when they purchase anything. And everyone wants the lowest price that will return the highest price resale later. RV's just don't work that way. First you purchase an RV not for investment purposes, but strictly for you own enjoyment. You have to ask yourself, how much am I willing to pay for pleasure! Second, RV's will break down, even the very best of them. Paint fades, propane tanks age, tires wear, wires will age and crack in time, electronics age out and technology constantly changes. My camper is a 2013 model, and it's already, technologically wise, ... ancient! Expect a loss in your finances. The thing that keeps all of us so dedicated to the RV lifestyle is not the cost factor. If it was determined on cost, none of us would ever do it. RV manufacturers and campgrounds would close up! We do it for the pleasure and enjoyment, and no amount of money is too much when it comes to our own personal needs for self-gratification!
Whatever make, model, and brand you ultimately select, you will find yourself forever investing money into it, and forever making changes, and forever doing repairs, fixes, and preventative maintenance. But, those of us who are engaged in this lifestyle.... the cost, the maintenance, the fixes are all part of the "pleasure" too. It's highly rewarding and satisfying when you have a problem with your camper (great or small), and you are able to figure it out yourself and fix it yourself. It truly is a life---style! And the longer you do it, the more it all becomes, simply,... part of your own soul.... who you are, and who you will continue to becomes.
Top brand? The one you finally own will be your "top brand."
Read, study, educate yourself, and look at lots and lots of RV's. When you purchase, you'll know what you are looking for.
Good luck!
