Hype Performance group H145 - still in beta and already beats all other aircraft visually hands down, and most of them functionally too. This will set a bar even very high quality large developers will struggle to attain!
Kodiak 100 - very very good visually and functionally. This (along with the H145) is the standard of what the best add-on aircraft should be!
JF Warrior/Arrow - not on the same level visually as the other two, but a huge step above most others with a very realistic flightmodel; and to me the best GA aircraft in the sim (if you don’t consider the Kodiak 100 a GA aircraft). I also fly Cherokees IRL so this is high praise… if only they looked a little bit better in the sim. Must-Have!
FlyingIron Spitfire - a legend, very very well executed, and it keeps getting better! Must-have!
There are many other ones that would easily make the list (like the DC6 or probably the CRJ, the JF Hawk, or the FBW A320, or anything by DC Designs) but neither airliners nor jet fighters are my thing so I cannot comment on those.
If I can add a wildcard to this it has to be @FlightSimUA and their Porter… not released yet, but even though they got a lot of competition from 2 other Porters they keep up their imensely detailed no compromise work, and definitely a great transparency and spirit! A role-model dev for everyone else. Let’s see how the plane will turn out, but I have a strong feeling it will be a top 3 spot next year
There are some developers that might make this list easily if only they’d be a bit more business savvy and kept their endless ranting about the sim (especially in its early days) to themselves (like the 2 hours incoherent stream rant by a well-known developer that creates very high-quality planes but I will never buy from them regardless)
Not an airplane, but no list is complete without @bijanstudio who came out of left field and singlehandedly created the best scenery mod for the sim with the by far best customer service I have ever seen from a dev
Same goes for @ScorpionFilm422 and his GNS 430/530/650/750 mods, these made a recent RL checkride procedural prep a breeze