• Thief, because they're the fastest class (I love fast characters) and use daggers/knives, one of ny favorite weapons

• Ninja, because they're fast too and can double wield fast swords (in the original, Ninja was the evolution of Thief, they only started getting separated in FFV forward)

• Hunter/Archer, because I love bows and long-ranged units (having a long-ranged unit can be the difference between a win or a loss)

• Beserker, because of their strong attacks and common use of axes (another of my favorite weapons. They're basically tanks, but usually also come with Berserk that makes them stronger, but uncontrollable. Personally, the more damage the better, so I don't mind at all)

• Gunbreaker, because gunblades are cool

And for the most of it, that's it. There's certain other details about a character that I like too, like if they wield a scythe (like Sice from Type-0) or use cards (like Setzer from FFVI and Ace from Type-0), or if they have the Slots ability (usually it's part of the gambler's class, but in some game it's hard to distinguish proper classes, you know).

Thief can be useful, I don't like to use them but if I ever see equipment I like I can always grab a thief, steal the equipment, than charm the enemies and watch them fight until someone gets hit.

In my experience, so Ps1 and Ps2 games, Steal is often pretty bad. Very low rates, depending on the game only one person has acess to it, in FFIV for example it comes too late in the game (Edge is one of the last characters you get, and he's the only one with the ability). So, for me, Steal has never been that appealing. The only game I use it so frequently is FFX, and it's because it actually works well there (good steal rates and stuff) and all the items are good for the customization of weapons and armor (and sometimes stealing is the only way to get said items). In other games, like FFIV, FFV, FFVI, FFVII, FFVIII, FFIX, even FFXII, I don't really use it that much (in FFXII I only use it up to 50 times to get Vaan's figure, nothing more).

I enjoy red mages as well, due to their versatility. I also like black mages and dark knights.

I do love Red Mages as well, if the option comes up, I almost always choose a Red Mage first, in fact, it’s what I started with in Final Fantasy XI. But I must say, I really love Dragoons, it’s how I beat Final Fantasy III, and I love their overall design and insane jump ability.