They may be a ragtag group of losers, but they're my ragtag group of losers!

[Realm25]

I always prefer heavy melee over magic whenever possible. Take FF1 for example, I'll always have either all Fighters, or all Monks etc, with just one Red Mage in there for some spells if and when I need em.

I use that set up for any RPG I play.

[ljkkjlcm9]

Usually focus on the physical as well, or those with the best unique attacks

FFVI: Shadow, Edgar, Sabin, Cyan
FFVII: Cloud, Barret, Cid (multi hit limit break)
FFVIII: Squall, Zell, Rinoa (Limit Breaks again)
FFIX was back to stereotypical.... Zidane(quick melee), Steiner(physical), Vivi(black), Dagger(white/summon)
FFX.... meh, never got far in it
FFXII: Vaan (high evasion dagger, time+arcane magic), Ashe (healing/katana), Basch (pure physical)

and in any other game, I prefer physical people as well.

THE JACKEL

[Wolf Kanno]

My first playthrough usually has me using my favorites or has people who might make a bigger impact on the story (see blackmage_nuke's post). In my second playthrough, I tend to focus more on gameplay so I tend to start using more unique parties and trying to discover secrets.

I build efficient parties that focus mostly on offense and speed. I rarely use magic users cause lets face it, modern JRPGs no longer make them a requirement since you rarely run into things weak exclusively to magic. Not to mention melee characters are starting to get uber special moves that allow them to hit whole groups of enemies once again making magics other strength irrelevant especially when the melee fighter tends to do it for free or at almost no cost. I also rarely use summoners cause they are quite overrated.

[Fate Fatale]

I mainly just use my favorites, but I make them work in a way that they don't suck.

FFVII: Cloud (Because you had to), Yuffie (quick melee), and Vincent (quick melee). I mainly just kicked ass in this game.
FFIX: Zidane (quick melee), Vivi (magic), Freya (melee), and Quina (tank). I didn't really need to heal that much, so a healer was unnecessary.
FFX: Tidus (quick melee), Lulu (magic), Auron (tank)
FFXII: Ashe (battle mage), Penelo (ranged caster), and Basch (tank)

There isn't really a trend. The games ahve become harder over the years though, so I need a healer more.