If you want the latest technology and features, the Apple Watch Series 8 is a good choice. It's likely to have a faster processor, a bigger screen, and more health-tracking capabilities. However, if you're on a budget, the Apple Watch SE is a more affordable option, and it still has many advanced features such as heart rate monitoring and exercise tracking.
In addition, if you have higher requirements for design and appearance, the Apple Watch Series 7 May be better for you, as it will likely have a larger screen and narrower bezels. Ultimately, your choice should be based on your budget, functional needs, and personal preferences.