depends what you're doing tbh. tor is for hiding your activity from your isp and browsing .onion stuff but it's slow as hell. mullvad is a vpn that hides your ip from websites but they still see all your traffic unless you use tor over vpn.
if you want real anonymity against big threats, tor wins. if you just want to stop tracking and get decent speed, mullvad is the move. honestly using both together is the best combo but that's overkill for most people.