For basic live monitoring: Petcube Cam
Petcube Cam is the lowest-friction choice when you need a clear live view and two-way audio in one known area.
For a pet moving around one room: Cam 360
Cam 360 adds remote rotation and a visible privacy position.
For food interaction: Bites 2 Lite
Bites 2 Lite is worth its larger body when remote treat tossing is something you will use regularly.
For laser play: Play 2
Play 2 is the specialized choice for pets that enjoy laser interaction.
For escape recovery: GPS Tracker
GPS Tracker solves a completely different problem: live outdoor location. It requires an ongoing cellular subscription.
For hydration: Fountain
Petcube Fountain is aimed at cats and small dogs that benefit from filtered moving water and flexible battery-powered placement.
Do not buy by brand alone
The best Petcube product is the one that solves a real problem in your household. A camera, tracker and fountain should not be compared as though they were interchangeable upgrades.