Tactics Ogre, a game for Super Famicom and PSX, has over 20 classes for ordinary humans (along with ten more for dragons and a handful of recruitable monster-characters.) I'll attempt to list them all:

Male Mundane Classes:

The beginning male class. They can use almost all weapons to some effect, but other than that they have no real advantages, other than being good cannon fodder.

A good staple of any army, they wield swords and can dish out plenty of damage and are very good at taking hits too, although they are a little slower than soldiers. Knights gravitates toward lawfulness, so making the hero a knight will cause the game to drift towards the lawful plot.

These guys wield axes and are even more effective offensively than knights. As a tradeoff, they're not quite as effective defensively and they're a little slower. They gravitate towards chaos, so making the hero a Berserker will cause the game to drift towards the chaotic plot.

The good ol' magic user, wizards specialize in offensive magic, lightning bolts, fireballs and all of that stuff. They're pretty effective, but unlike fighting classes you have to give them time to become deadly, be patient. They wield staves and wands and are a little quicker on their feet than any of the above classes.

Beast Tamer:
If the monster-characters in your army are very important use one of these guys. They wield whips, and improve the attack power of monsters around them. However, since you can only have two monsters on the battlefield at one time you are effectively giving up three ranks in the battlefield for them.

Ninjas wield claws and daggers are very fast, they can scale heights normal characters cannot, allowing them to do things such as jump around rooftops and then dive right into the rear of some enemy troops. Ninjas also have the ability to wield two weapons at once and they can cast some rudimentary magic.

Female Mundane Classes:

Essentially the female version of a soldier.

Extremly effective if they have high ground. They can scale heights almost as effectively as a Ninja, so hopefully they can get on a rooftop quickly. They're faster than most other units and, obviously, wield bows and crossbows. Three archers with good field position are very hard to stop. Unfortunately, Archers are not very useful when fighting uphill as their range drops dramatically.

Clerics wield wands and staves and are absolutely essential in any army. They cast protective magic, particularly, healing. They only other classes that can do this early on are Exorcists and the protagonist's sister (who you have no control over on the battlefield.) Like the archer Clerics are relatively fast.

Witches are essentially the opposite of Clerics when it comes to magic but similar in every other aspect. They cast magic of attrition such as poison, stun and charm.

Male High Classes:

You get one of these guys early on. They can cast some healing magic, but they are more often used because they are the only class which can cast the spell "Exorcise." Which is the only way to permenantly destroy the undead. When not fighting undead it's a good idea to have your Exorcist fight as a Wizard or other, more useful class.

A very powerful Wizard, he can use some of the more destructive spells.

Dragon Slayer:
Basically a Knight for killing dragons. Most other units will have lots of trouble trying to kill a dragon, but these guys can take them out easily. A Dragon Slayer must be neutral. The one major distinction between them and Knights is that they are slower still.

Terror Knight:
A deadlier Berserker who reduces the effectiveness of enemies around him because he's just so scary. He's pretty slow, but very powerful.

He wields guns, and, so long as there's nothing in his line of sight can shoot all the way across the screen. Placed on high he's even more effective than a pack of archers. He must be neutral.

Sword Master:
In Final Fantasy Tactics, Thundergod Cid is one of these, and, if you've ever played that game, you'd know how effective he was. Unfortunately, in Tactics Ogre the Sword Master isn't that great. They have the ability to wield two swords, are very accurate and can cast a little magic. However, they're no good at dodging attacks, are very slow and are not that powerful to begin with. They must also be lawful.

Female High Classes:

They wield spears, are faster than knights or berserkers and can cast some magic. They're also a little weaker than their male counterparts

They are much like clerics with some unusual restrictions. For one, a Priestess can never kill more than 5 others in her lifetime, second, she can only be lawful. They can, however, ressurect dead characters, which more than compensates.

Essentially a cross between a witch and a wizard. They wield staves and fans.

Dragon Tamer:
Essentially a female Dragon Slayer. They're actually more powerful than their male counterpart, and also improve the effectiveness of your own dragons.

The one other class I'll mention here is that of the Lich. If a powerful magic user wearing the Ring of Death dies, and they meet certain criteria they will come back as a Lich. A Lich is undead, and a better magic user than most other classes of either gender.