This depends on where you’ll be using it.
Bathroom mortice locks are operated via a thumbturn on a bathroom lever handle (or with a door knob set and a separate thumbturn) and can be opened via a coin from the outside in case of an emergency.
Euro cylinders are common in newbuilds and are often used with a Euro sash lock (mostly on patio/conservatory doors) or with multi-point locks (mostly on modern front doors).
Mortice latches are usually used for internal doors which don’t require locking.
5 lever sash locks are the most secure option and are recommended for exterior doors.
Locks/latches are also either Standard or Heavy Duty, which refers to the strength of the spring inside. Standard variants are used for sprung handles, whereas Heavy Duty is recommended for unsprung, or particularly heavy, handles which need help returning to their original horizontal position.