Every character was great in their own way, even Edward. Edward was a good character in that he showed that you don't have to be the most stalwart, physically imposing of men to still show bravery.
Choosing favorites from this game is like choosing favorite children, but if I had to point out the ones that deserve EXCEPTIONAL credit:
CECIL: The embodiment of how many men want to live their lives; Cecil shows how we seek to conquer the malice and cruelty of our own personalities to live a life towards a better cause. CID: FFIV's version of that crazy, pudgy uncle of yours that helped you light off M80's on the 4th of July. YANG: Fierce and deadly, dutiful and loving, a good role model for Cecil (and ultimately, the player). EDGE: The firecracker smart a$$ friend of yours, the guy who gets the team fired up. ROSA: All men should be so lucky to have a beautiful and devoted woman on their arm. Having her be an expert archer and be able to heal wounds instantaneously is a nice bonus. GOLBEZ: Proof that its never too late to realize the error of one's ways, and proof that blood is binding in all travels of life.
EDIT: One last one.... RUBICANT: One of the slickest and most powerful foes you'll come across, an incredibly worthy adversary that maintains honor, Rubicant merits further investigation as a character, and should be given a chance to be a hero in some future title (wishful thinking....).
Man, I think someone should hack IV, and create a super-powerful Rubicant, with special spells (Meteor could do 50,000 damage), and over 5 million hit points. Yeah, sure, it'd take you hours to beat him, but that's the price you pay for fighting him.
Kain is my favourite, followed by Rydia, and then FuSoYa. YES, you read that well. No, I don't know why I like him so much. It must have something to do with the fact he looks like a mop when K.O.ed. Cecil is not too short behind.
Yang's Wive also has a special place in my heart. A woman who has the guts to order a righteous paladin to hit her husband on the head with her frying pan next time he sees him is an awesome woman in my books. We know it's not Yang wearing the pants in that relationship.
Rydia FTW. She's the first and the best summoner in all of Final Fantasy. She also knows black magic and has really nice green hair, so that's a huge bonus.
I think Cecil is one of the best characters ever in the whole series. All of these characters were so well developed for their time. The chibi-style of the DS remake really makes me angry because Cecil had real integrity to his character and I think the appearance of the characters will really ruin that integrity, also, it was kill the coolness of Kain.