In my opinion, Morgan is the best fighter. To be a 'good' fighter a lot of skill is required, and skill is not just shooting a gun (as most people who have survived this long can shoot a gun). Skill requires you to deal in any scenario and Morgan is a perfect example of this. His preferred weapon is his kendo stick in which he gained from his master.
He has the ability to tackle any obstacle with this weapon, wether that be walkers or in fact people, shown by his desolation of the 'Wolves'. Morgan also passes on his abilities by teaching Ben to use the kendo stick as well.
Secondly, a part of being a great fighter (in the walking dead) is defence against the walkers. The second time Rick meets Morgan is in his house of horror-like fort, in which Rick narrowly escapes an axe to the face. Morgan (apart from being a psycho at this point) was cautious. He knew when to sit back and protect himself but also when to engage and defeat his enemy, enabling him to survive for longer
He saves Rick from a street full of zombies at the beginning of the story. He saves Maggie despite he was tied to the chair and locked with a zombie.
He said, People you love... they made you who you are. They're still part of you. If you stop being you, that last bit of them that's still around inside, who you are... it's gone.
Glenn risked his own life many times for the people he cares about. He went down a well for save his people's water. He brought a pregnancy test for Lori. He saved one of his enemy (Tara Chamlber). He risked his Life for trying to save Tara when her foot got stuck under a rock. He saved his another enemy again who is try to kill him (Nicholas) and became friend with Nicholas. He survived while he was shot and 2 zombies swooped him in a forest. He did NOT kill any human being till seventh season. He was one of the most zombie killer till his dead.
He was real hero, real lover. After taking 2 blow to his head, while he was nearly death his last words were “Maggie, I will find you”.
He saved, he loved, he forgive.
He said about Enid's parents; They are still here because you are still here. to Enid. I agree with him. He still here, in our heart.
If I had to make a top 5 list, it would ;
1. Glenn Rhee
2. Daryl Dixon
3. Rick Grimmes
4. Negan
5. Carol Peletier
"Cheers"