Prue was for me because of the sacrifices she had to make to ensure he sister's were better off. The lovers she had lost. Giving up on a social life. Last but not least her life for the greater good. Plus she had kick ass powers.
Piper too was great. Her powers were great and she has three beutiful children that will grow up to be even more powerful than her. She had to take up her sister Prue's role as Big Sis.
Phobe was the youngest till they discovered they had a sister. She had to overcome all the rotten boyfirends she had most of which had a dark side bar the last 3. Plus she gets to levitate and see the future which is so cool. Best of all she ends up with Cupid.
Lst butnot least Paige. she has her witch powers as well as her white lighter powers. She's honed her skill, met her bio dad had a string of boyfriends.