#1 - Light Yagami
Now don't tell me that you haven't watched "Death Note".. It's an awesome anime go check it out. Let's get this straight Light yagami is able to kill anyone the way he wants in just seconds just by writing the persons name he want to kill in his Death Note.
#2 - Goku
Goku is a God type character like Saitama casue he is capable of destroying Universe. In his fight with Beerus he almost destroyed it as the Chi Blasts from their battle started wreaking havoc in the universe and he has Instant Transmission so he might be able to beat Saitama.
#3 - Ichigo
Once again if your reading Bleach manga you might know right now Ichigo's power has doubled than he had in the series and he still haven't unlocked/mastered his quincy powers so after he do that he will be more powerful so he has a chance to beat Saitama.
#4 - Kami Tenchi
He can destroy universes and dimensions. This is of no surprise that he can defeat Saitama.
#5 - Monkey D. Luffy
Luffy would win because he is not effected by any normal punches and Saitama would have a hard time punching him.
#6 - Lelouch Vi Britannia
Lelouch is one of the smartest anime character in anime history. With his Geass he can order anyone to do what he wants anytime.
#7 - Anti-Spiral King
Now Saitama is in danger , his king can throw galaxies . They say Saitama cannot stand up against that much power.
#8 - Kuro Sensei
If you have watch this anime you might have an idea about this. Kuro Sensei is known as God Of Death before he turned into a being , he can move at the speed of MACH 20. Saitama might outrun him with his speed but Kuro Sensei is a experienced Assassin so he might be able to assassinate him.
#9 - Sasuke Uchiha
Now you now Sasuke. He is also one of the smartest character in anime history and this is what he can do, He can send Saitama to another dimension and let him die of starving, His amaterasu will keep on burning him until he is dies (Amaterasu - A Black Fire which cannot be extinguished unless the user stop it), However Saitama is physically stronger than him.
#10 - Ban
Now Ban is immortal (He drank from the fountain of youth) . He is strong as hell and the best part is he can drain his enemies power over time which allows him to drain Saitama's power and it will make Saitama weak which means Saitama will be killed.
