Best Kits

When I started out making plastic airplane models as a kid, there were few big kit makers, with Revell being the most common.  Over the years, the modeling industry became much bigger world-wide and other manufactures gained bigger shares of the market. Today there are a number of international kit manufacturers producing better quality kits than Revell.  As an adult modeler, I have only built a few of their kits when they offer the only source for a specific model.  

As a general rule, you should purchase the model you are looking for from any manufacturer; you can always work around some of the quality differences to make a great model. Modelers are very particular about quality; so what I do mean about quality? The best kits have very detailed pieces keeping to scale, using the best molds to make parts that fit up exactly and come with easy to follow directions.

The big majority of kits are plastic (styrene). This is because they are made using injection molding and the metal molds can last for thousands of uses, making it economical to mass manufacture quality kits. There is a small market in resin kits, where you can find specific models not made by the big manufacturers. Resin parts use rubber molds only good for a few uses, and are made by dedicated individuals who make a few kits at a time. Resin kits will have less detailed small parts and are more expensive. I have built only a few resin ship models, again, only because that was the only choice for the specific ship I wanted.

I would recommend the following kit manufacturers base on overall quality and ease to build:

Tamiya
Tamiya is well known for the last 30 years to make a good variety of high quality armour, aircraft and warship kits. I think their warship kits are the best available and I always see if Tamiya makes the next ship I want to build. Their amour and aircraft kits sell in the $15 to $50 range, while their warships are in the $50 to $200 range (a lot more parts and precise molds).

Trumpeter
Trumpeter is also very popular and offers warships not made by Tamiya. I have built several of their warships and there have been some minor fitting issues but still a good choice.

Academy
Academy (previously marketed as Accurate Miniatures) also has all three types of kits. I have been pleased with their 1:48 aircraft with the only issue being poor instructions (use of Youtube helps!)

Hasegawa
Hasegawa's quality is right there with Tamiya. They don't offer armour, however.

Others:
There are other kit manufacturers (Airfix, Eduard, Italeri and Dragon) that are popular and should be good builds. I haven't purchased from them so I can't personally compare them but if you find the model you want they should be fine.

Aftermarket Suppliers
As the modeling industry grew over the years, speciality parts suppliers became viable and they have added much to our ability to make more detailed models and better display them. The best example is the PE (Photo-Etched Detail) suppliers such as Eduard, Tom's Modelworks, and White Ensign.  Other suppliers have decals, figures, display bases, and dioramas to add to your model. You can also find display case suppliers who will ship you a specific base and acrylic case to keep your models dust free.