Below are my personal setups for all the playable characters in the original Suikoden along with any notes I may have. While nothing can truly be considered the "best" due to varying play-styles, I try to set my characters up to strike a balance between offense and defense and address their weaknesses while magnifying their strengths as well. More importantly, I use a character's traits and personality as a base to what I believe they would use. If at anything, let this be a template for your own decisions and have fun with it. See Chapter 14 of my guide to acquire any of the items used below.
Tir
Flik
Viktor. Killer Rune would be more useful, but I use Clone for some diversity.
Camille
Rubi
Kreutz
Sylvina
Griffith
Gremio
Pahn
Cleo
Tai Ho
Kuromimi
Kirkis
Valeria
Eileen
Lorelai
Stallion
Yam Koo
Lepant. Killer would be best for more offense, but Lepant has enough MGC to be a mage as well.
Krin's the perfect candidate for the Spark Rune, but the Killer Rune makes him somewhat useful offensively.
Juppo
Kimberly
Humphrey
Mose
Sheena. Lightning Rune permanently attached, but still a great character.
Hix
Kai. Hazy Rune cannot be replaced, unfortunately.
Sydonia
Fukien
Gen
Meg. Cyclone or Thunder Rune recommended if you don't like Trick. Guard Robe can't be removed.
Luc. Guard Robe armor is locked.
Liukan. Can use a shield, surprisingly. That and high SKL makes him useful as a fighter as well.
Ronnie Bell. Guard Robe highly recommended due to her extremely low MGC.
Kage
Fu Su Lu. Might consider Mangosh x2 as his hit% is incredibly low, but so is his MGC.
Fuma
Mina. Magic Robe and Toe Shoes are both locked, so watch her damage closely.
Blackman
Kirke
Sarah
Antonio
Lester
Clive
Crowley. His Emblem is locked, which is unfortunate, cause he doesn't need anymore MGC.
Kasim
Sonya
Futch
Anji
Alen
Varkas
Kamandol
Eikei
Gon
Grenseal
Hellion
Kasumi
Kessler
Kanak
Kwanda. Walking tank.
Leonardo
Lotte
Maas
Mace. Weapon stuck at lvl 15 due to being unable to sharpen his own weapon.
Milich
Meese
Morgan
Milia
Moose
Pesmerga. For whatever reason, his Dragon Armor is locked.
Quincy
Sansuke. He needs a Hazy Rune as he takes an absolute beating in the front row.
Sergei. Almost non-existent offensively. He can be of some use as a mage in the back-row.
Tengaar
Warren