This ultimately comes down to how you plan on using it. For runners, something like the Forerunner 745 is going to be your best option. It offers in-depth tracking capability that does more than just pace and distance. Rather, you can look at a wide range of tracked data to help you improve your running style. There's even a handy workout recommendation feature that can help those training for events like a 10k or full marathon.
Similarly, avid outdoor athletes should consider either the Epix or Fenix 7. Both watches are Garmin's rugged, high-end wearables that offer everything from built-in GPS and a pulse oximeter sensor to advanced sleep monitoring, hydration tracking, and in-depth mapping content. In other words, these should be the go-to companion for anyone venturing into the backcountry.
Beyond those use cases, Garmin's wider range of watches is perfect for people of all fitness levels and skills. The Venu 2 is a sleeker model that has advanced health and wellness monitoring while something like the Vivoactive 4 is an understated yet stylish activity tracker that's perfect for beginners or first-time wearers.