There are only two types of people in the world: one who absolutely love One Punch Man, and other who strongly dislike it for being too predictable. Now finally that the anime is over, I can review it properly.
One Punch Man is an action-comedy anime which tells a story about a man named Saitama who is 'a hero just for fun' in a world where monsters and heroes are quite common. He is quite overpowered and manages to kill anyone in just a single punch, which has made his life quite boring. Soon a new cyborg named Genos is introduced who is in search for another robot who destroyed his village and he later requests Saitama to become his master after seeing his strength.
At first the story sounds quite predictable and the idea of killing anyone in a single punch adds more to it. Yes, it's true! It becomes a little predictable and the humor of killing anyone in a single punch dies off quickly. But the anime doesn't has only that much to offer. The story starts developing from 5th episode with the introduction of Hero Association and a ranking system which classifies heroes into C class, B class, A class and S class having rankings in each class. New characters are introduced and the story becomes more interesting. The last two arcs were very good, so just don't drop the anime in your early episodes thinking that it's getting predictable or is not worth watching.
This is the best element of One Punch Man! The art of this anime is fabulous. Madhouse has again done a wonderful job. The backgrounds are really well done and the fighting scenes are amazing. Infact One Punch Man and Fate/Zero are the best graphics anime I have seen in my life! One Punch Man is actually a pretty average budget anime. The secret behind One Punch Man's amazing graphics lies behind the fact that it has been directed by Shingo Natsume (Key animator of Gurren Lagann, Fullmetal Alchemist: Brotherhood, Hachimitsu to Clover), assisting Kazuya Murata and with the legendary Kenichi Konishi supervising the animation, Sejoon Kim (animator of Gundam) as a regular animation director. Another notable element of One-Punch Man's visuals is the digital animation, something also tied to Natsume's presence. Other than the animation staff, there is someone else who deserves special credit. People who have read Yusuke Murata's version of One-Punch Man – the one the anime is based on – know that even before the anime, the series already was animated. Sort of. Sometimes rather arbitrarily, Murata would go on to draw sequences step-by-step with a ridiculous level of detail, almost as if they were key animation sheets. Something he is capable of putting off because he's an exceptional and dedicated artist, but also because he is a fan of animation.
Another element of One Punch Man which makes the show amazing! Opening and Ending song, both are wonderful. I keep listening to both of them over and over again because they are that awesome. All the OSTs are also worth listening to, and some are just superb which may give you goosebumps! Voice acting is also top notch. Many talented voice actors like Miyano Mamoru, Sawashiro Miyuki, Kaji Yuki, Sakurai Takahiro, Nakamura Yuuichi, Hayami Saori, Namikawa Daisuke etc are there and they have done a great job.
All the characters are quite likeable. They have unique personalities and possess a unique charm in themselves.
I will write a few words on my (and people's) most favorite characters from One Punch Man:
1. Saitama - Our favorite hero, the protagonist of the show, quite humorous.
2. Genos - Saitama's partner, best disciple, cyborg and cool.
3. Mumen Rider - C class hardworking hero who rides a cycle but is physically pretty weak to fight with monsters but is very courageous and hardworking/
4. Sonic - A ninja! What more? Everybody likes ninjas (Naruto haters please keep it low! -_-)
5. Tatsumaki? - You know what I am talking about if you have seen 11th episode of One Punch Man! ;) [If you still don't understand, let me know -_-']
I really enjoyed One Punch Man because of it's intense action which were beautified by amazing graphics and coated with amazing soundtracks.
If you like action-comedy (with frequent serious arcs), adventure and superpower anime, and elements like graphics and sound are an important factor for you then you MUST WATCH this anime! Even if you don't like all that, you can give it a try. I assure you that One Punch Man is NOT some random cliche anime which has random power boosts which makes it impossible to watch. It is quite entertaining.
P.S-Comments appreciated :)