Action is the widest label in games, which makes it close to useless on its own. What people usually mean is one of three things: combat with real depth you get graded on, spectacle you get carried through, or movement that is fun before anything else happens. Deciding which one you want narrows 800,000 games down to a shortlist very quickly.
A good action game gives you a small set of verbs and then spends the whole game finding new questions to ask of them. The bad ones keep adding buttons instead. The test is simple: an hour in, are you getting better, or is the game just handing you more numbers?
The style meter is the genre's defining invention: finishing a fight is not enough, you have to finish it well. Expect a deep move list, weapon switching, and a difficulty ladder that goes far past the default.
Combat is deliberately narrow so that every hit lands hard and the camera can do the work. These are the ones to play when you want to be impressed rather than tested.
Some action games are really about getting from one place to another. The fighting is an excuse to keep moving, and standing still is the losing move.
An action RPG gates your power behind stats and gear, so getting stronger is a progression you buy. A pure action game gives you the full move set early and expects you to get better at it yourself.
If you want depth, Devil May Cry 5 or Bayonetta. If you want to be entertained without being tested, God of War (2018). If you mostly want to move fast, Titanfall 2.
The combat-led ones age very well — the systems were the point and they still work. Spectacle-led ones age worst, because the spectacle was tied to what the hardware could do at the time.
Start from something specific rather than from the genre:
Or by the machine you own:
Or start from a game you already love — every title we cover has a page of hand-written recommendations, and the best-games lists cut the same library by era, audience and mood.