HardwareSerial is the best choice (Serial1 on Leo, Serial1/2/3 on a Mega or Due). It is possible to use Serial on any Arduino, but you would have to disconnect pin 0 to upload new sketches. You would have to be careful about printing to the Serial Monitor window, because those prints would also be sent to the HC-05. And anything you print to the HC-05 would also be shown on the Serial Monitor window. This can help with debugging.
AltSoftSerial is the second best choice, but it only works on two specific pins (8 & 9 on an UNO, Nano or Mini).
NeoSWserial is the third best choice. It works on any two pins, but only at baud rates 9600, 19200 and 38400.
SoftwareSerial is the worst choice. It is very inefficient, because it disables interrupts for long periods of time. This can interfere with other parts of your sketch or with other libraries.
AltSoftSerial and NeoSWSerial are available from the Arduino Library Manager, under the menu Sketch-> Include Library-> Manage Libraries.