My two favorite teams:
Riou - Of course, our hero. Some people prefer to use him as a physical attacker since he has good physical stats (DEF is the lowest at only 125 by level 60), but I loved the Spark/Bright Shield/Flowing/Magic Drain setup and I have since made it my standard build for him.
*Bright Shield offers healing and light-element magic like no other; Battle Oath and Forgiver Sign are just awesome.
*Spark enables slowpokes like Bolgan to attack first before most enemies since Riou has good speed (only Nanami, Shiro, Kasumi, and Stallion are faster than him, and I use Nanami as my Spark rune bearer and back-up supportive mage).
*Flowing gives out Kindness Rain at Level 2, something that I really need to make use of since Shining Light from the Bright Shield rune isn't exactly very damaging, even against the undead. That's why I have suggested that Bright Shield spells should be based on Riou's Resurrection affinity (at B, it's the only high affinity he has).
*Magic Drain on Riou's weapon allows him to spam Great Blessing for minor healing pretty much all day.
Viktor - one of the best physical attackers in the game. DB/DS/Friendship is easy 400+ ATK and 500+ damage per strike (not per turn) to normal enemies.
Flik - the best Mage Knight in the game after Jowy, whom we can't use for long. Decent attack power, nice Unite with Viktor, high MAG (9/6/3/2 at level 60) and good affinity to Lightning and Fire elements (B in both) and okay affinity to Earth (C). Thunder + Rage = Blazing Camp, GG.
Eilie - good stats overall, good unite with Rina and Bolgan, and a decent mage with 8/5/2/1 MP at level 60 and nice affinity to Fire and Earth (B in both).
Rina - one of the best magicians in the game; high MAG (same MAG as Flik), B affinity to water and C in everything else, making her both a good healer and a good offensive mage with *Blue Gate (its last two spells base their damage on the user's Water affinity).
Bolgan - not exactly a star character since he has no free rune slots but he has pretty high STR (180), DEF (140), and HP (680); good armors, and a nice Unite with Eilie and Rina, so I use him as the party tank. Skill Ring + Thunder Amulet should help offset his low TECH.
See my Riou setup above.
Hix - One rune slot but has a permanent Exertion rune so it's all good. I use either Double-Beat so he can attack twice per turn, or Double-Strike to increase the damage of his Unite Attack with Tengaar.
Gadget - Has the highest natural DEF in the game, 400 DEF at Level 60 is piece of cake for him, so even the strongest enemies in the game can't touch him unless they use magic, which he has pretty much no defense against. Equip Meg with the Lubricating Oil from the Rope Climbing game and watch a Berserked Gagdet deal 500 damage to all enemies with their Unite Attack.
Tengaar - One of the best magicians in the game; she has the same MAG as Rina and Flik (9/6/3/2 at Level 60), and actually has better overall affinities than Rina (B in Earth, Fire, and Wind), although she can't use *Blue Gate. Her unite attack with Hix is awesome, though she damages Hix with it. However, it appears to be only at a certain percentage, so it's not possible to kill Hix with it. Nonetheless, pretty awesome but underrated character.
Millie - One of the best underrated magicians in the game. Sure, she's nowhere near as powerful as Luc, but she's the only character aside Mazus to have A affinities in two of the most commonly used offensive elements in the game: Fire and Lightning. So expect her Fire and Lightning spells to pack quite a punch despite only having 8/5/2/1 MP at level 60. Although she can use Blue Gate, it's not advisable because she has bad affinity to Water (E), so Pale Palace and Empty World can backfire. However, if you still want her to use BG, that's fine as long as you don't use both spells. I would instead use *Rage, or *Thunder if I already have another Fire mage (like Tengaar or Nina).
Meg - Pretty underrated as well; bad attack but she has one of the highest critical rates in the game (10.78%); second only to Riou, Shin, and Shilo (11.25%). Although she has a pretty bad MAG stat (only 7/4/2/1 at Level 60), she has an A affinity in Lightning and Wind. Meg can actually deal Lightning damage comparable to that of Millie, an A-rank Lightning mage with one MAG rank higher. But then again, they're no Luc or Mazus. Although her damage is not counted in her unite with Gadget, it's pretty awesome to see him annihilate Highland soldiers in the final dungeon with it.
As always, Friendship and Exertion are my go-to Weapon Runes for fighters, then either Down, Rage, or Thunder for L-ranged magicians or for other fighters when I have already used Friendship and Exertion, and S-ranged magicians except for battle mages like Sierra (has a permanent Thunder rune on weapon) and Zamza in front shall have Mother Earth runes on weapons.
I usually equip my parties with resistance gears rather than power gears because the final dungeon is pretty magic heavy even with the usual appearance of Highland soldiers inside.
Lucia uses Dancing Flames (Lv2 Rage spell) and a nasty target-all spell (Hellfire from Suikoden 3?).
Bronzem has a normal attack (affects DEF), a column-wide Earth-element normal attack (affects DEF), and a target-all Earth-element magic attack (affects MDEF).
Magus has a Fire-element Hadouken magic attack, and a very nasty Flaming Arrows spell.
Chimera has three heads. Eagle Head has a column-wide Sonic Scream magic attack, the Lion Head has a target-all fire attack, and the Goat Head has a column-wide Rust Breath. The Rust status works like Stone in the FF games, but unlike FF it can be healed by healing spells, NOT restorative items except Sunomono from Hai Yo's kitchen.
Seed uses Explosion (Lv3 Rage spell) and Silent Lake (Lv3 Flowing spell), while Culgan uses Thor Shot (Lv3 Thunder spell) and Kindness Rain (Lv2 Flowing spell) and buffs Seed with a Thunder Sword Rune spell, which will appear in Suikoden 3.
The Beast Rune's Left Head mostly uses Water-element attacks. The Right Head's Sword Attack is a fire-element normal attack. The Rune Part's Dark Dragon attack is a dark-element normal attack, and only Silver Armor and Silver Shield gives resistance to dark. The Beast Rune's Unite Attack reduces everyone's current HP to 25%, much like the Demi2/Graviga spell from the FF games.
If you're not worried about magic damage, then fine, you can use a power build if you like. But if you only want to know what elements are needed for the final dungeon, you don't need a Wind-element resistance for this one. However, the best Cap-type head armor in the game is a Wind Hat, so you can't really avoid it unless the character is a Helmet-type, in which case s/he can equip a Flame Helmet and replace the redundant Fire Emblem with a Power Ring.
It's not all about knowledge, but it helps.