This is not an easy question, as it vastly depends on which kind of person you are talking to. He or she may be a gamer, an aviation enthusiast or an experienced pilot...and may prefer a long peaceful flight in an airliner, a scenic bush-flight over a wild region or an historically accurate air battle.
Therefore I typically reply with another question: what would you like to do in the simulator?
Depending on the question I will try and direct them to the simulator that may be the best fit between the ones I know (relatively) well.
So, as a quick recap and a go-to reference for the people I speak with, here is what I think of the simulators I use the most, and what I believe to be their strong and weak points as of today April 20th 2019.
But first, a word about the hardware:
In general you need a fast computer (I'd say a 3.0 GHz quad core minimum) and a good graphic card (by today standards a GTX 960 is probably the bare minimum). Some simulators run better than others, but running a modern flight simulator without a good computer is an exercise in frustration. A Windows PC is preferred over an Apple computer since not all the simulators are available on the latter.
Along with a fast computer with a good graphic card, you'll need memory (some sims can run with 4Gb but 8Gb should be the standard) and a sizeable available space in your hard drive. The required space will depend on the add-ons you will use, but I'd say that 256 Gbyte is the bare minimum...but be warned that many simmers typically have dedicated hard disks with 1 Terabyte or more: some add-ons (and in particular high detail photoreal sceneries) take a lot of space.
One last thing before we start: you'll need a flight stick. You do not necessarily need a replica of a real one, and you can buy a decent one for 40-50 Euros or less. But trying to use a flight simulator without one will drive you crazy. Be sure that it features a throttle control and a "twist" motion for the rudder.
Prepar3D v4
Published by: Lockheed Martin
Latest version: 4.5
Price: USD 59.95 (Academic); USD 199,95 (Professional)
Available on: Windows (64 bit)
Several years ago, Lockheed Martin acquired the rights to the Microsoft ESP platform, which was basically a tentative to market Flight Simulator X for professional simulation / visualization purposes. Lockheed Martin has constantly upgraded this simulator, adding a new rendering engine and a 64 bit code and maintaning a good backward compatibility with FSX. With the failure of Microsoft Flight and Dovetail Flight Simulator World, Prepar3D is the "de facto" heir to the venerable Flight Simulator legacy.
Disregard the incredibly expensive "Professional Plus" version which is meant for military use.
Strong Points:
- Backward compatibility with many FSX add-ons means that there are literally thousands of good quality add-ons, either free and payware. It is highly likely that a good rendition of your favourite plane or airport alreadyt exist for this simulator.
- Very flexible experience: you can fly anything from a glider up to a 747 anywhere around the world.
Weak Points:
- Default content is not great and the base scenery is outdated (looks a lot like Flight Simulator X). You'll need some add-ons to make it look good.
- Needs a very powerful computer to run well.
Recommended to:
Basically anyone who has an interest in flight simulation...but be warned: the default content is not great and you'll need to get some add-ons: there are some great freeware ones, but the best ones are typically payware.
Not recommended to:
Users who have no will to look for (and eventually buy) add-ons to improve the simulator.
Users interested in air warfare simulation: while P3D has a wide choice of (excellent) military aicraft, it does not support weapon functionalities by default (unless you buy the professional plus edition - which I do not recommend) although it can do that with packages such as vACMI, Tacpack or others. If you are interested in air combat you should first check DCS.
X-Plane 11
Published by: Laminar Research
Latest version: 11.33
Price: € 64,99
Available on: PC, MacOS, Linux
Strong Points:
- Simulation engines is based on an actual fluid dynamics model: arguably a superior approach with respect to table-driven engines like the one of FSX/P3D.
- Graphic engine runs well and does an excellent job in portraying small scale details.
- Some of the default aicrafts are really well done.
- Fantastic night lighting effects.
Weak Points:
- Default terrain textures are quite bland and repetitive. You'll need add-ons to make it look good.
- During the day, the default lighting engine is not great (poor water rendition, bland daylight brightness and shadows, poor cloud rendition).
- While there are some excellent add-ons out there, P3D in my opinion still has the lead with a wider selection of better quality add-ons (but the tide is changing).
Recommended to:
Basically anyone who has an interest in flight simulation. It is a great simulation and does a lot of things better than P3D (but not everything). If you have an Apple or Linux system, this is the best flight simulator you can buy. If you have a PC, choosing this over P3D may depend on your computer and which add-ons you would like to use.
Not recommended to:
Users interested in air warfare simulation: while XP-11 has a limited support for weapon functionalities, DCS is the simulator your should check first if you are looking for military flight operations
Aerofly Flight Simulator 2
Published by: IPACS
Latest Version: 2.
Price: € 59,99
Available on: Windows (64 bit), MacOS, Android
Aerofly FS 2 started as an attempt to bring a decent flight simulation experience to high end mobile devices and then was scaled up to a fully-fledged desktop experience. While its heritage still shows in the user interface, the fact that the simulator was designed for the limited resources of a mobile device makes it so that it runs really well on desktop computers, providing exceptionally good frame rates even if your hardware is not the latest and greatest. However there is no traffic, no multiplayer, no ATC and basically no weather system. It is just you, your plane and the photoreal scenery.
Strong Points:
- Exceptionally efficient graphic engine: runs really well and provides a fantastic performance in Virtual Reality.
- Very sharp photoreal textures (default scenery covers the majority of the western United States).
- Excellent choice of good quality default aircrafts. Both external and internal models are done really well.
Weak Points:
- No ATC, no traffic, no multiplayer: it is just your aicraft and the scenery.
- No water shaders, no cloud shadows, very basic clouds and almost non-existent weather system.
- Scenery coverage is limited to some areas of the world (coverage is slowly being expanded through add-ons).
Recommended to:
Anyone who would like to fly over a super-sharp phoreal rendition of the State of California or over the Grand Canyon. Flying in Virtual Reality is very impressive in terms of immersion and "feeling" due to the exceptionally high frame rate.
Not Recommended to:
Anyone looking into something more than basic flying: absence of traffic, ATC or multiplayer is a big drawback. And needless to say there are no military functionalities.
Digital Combat Simulator (DCS)
Published by: Eagle Dynamics
Latest version 2.5.4
Price: base software is FREE (one map, two planes)
Available on: Windows (64 bit)
Starting from the heritage of a successful combat flight simulator like Lock-On Modern Air Combat, Digital Combat Simulator (DCS) has become arguably the best air combat simulator available on an home computer. You can download the base software for free but it only features one map (Caucasus) and two planes (SU-25 Frogfoot and the TF-51 Mustang) - then you can buy a number of sceneries such as the Persian Gulf or the Nevada training range, and a growing selection of excellent aircrafts (including the F-14 Tomcat, the F/A-18 Hornet, the A-10 Thunderbolt and the AV-8B Harrier II). These add-ons are not cheap...but they are extremely realistic and detailed. WWII and Korean War warbirds are available too. DCS also includes a detailed simulation of ground vehicles and ships.
Strong Points:
- Excellent rendering engine providing good performance and great scalability to small details
- The general quality of the add-ons is outstanding: while some of the planes are a little expensive, they are typically the best rendition available of the machine they depict.
- Arguably the best combat environment you can play on your PC
Weak Points:
- Some ground texture repetitions
- Weather engine is not great in some instances
- Scenery is divided in "maps" you need to buy. While they are large, you cannot fly anywhere in the world.
Recommended to:
Anyone interested in digital military simulations. DCS is the best combat simulator on the market.
Not Recommended to:
Anyone not interested in air combat. You may also want to check in advance if your favourite plane is or will be available for the platform, since the current selection of vehicles is somewhat limited.Other Simulators:
The simulators listed above are the ones I know and use on a regular basis. But there are many Others you may want to consider… here are some of the most popular:
Flight Simulator X is still available on STEAM for 24,99 euros, although I think it is outdated and I do not recommend buying it. You may still consider it as an option if you do not own a high end PC.
Flight Gear is a collaborative effort to create an alternate, open source flight simulator platform - I have not checked it in a while but it seems way behind the simulations I have mentioned above.
If you are looking to WWII combat simulator, IL-2 Sturmovik is still considered by many the best simulator in that niche. I have to confess I have not tried it.
Believe it or not, Falcon 4.0 has still a large dedicated community that over the years has improved it considerably. Frankly I have not checked it in years and I think it is outdated.
...and then there are a many other simulators I have not played. But again these were just my two cents.