This article is from the Final-Fantasy and other Square Soft Games FAQ, by firstname.lastname@example.org (Nick Zitzmann) with numerous contributions by others.
Here's some of the items to look out for when playing FFL II:
Parasuit: The Parasuit is a full suit of armor for a character (kind of
like the Power Armor from FFL I.) Humans and mutants can't wear other
pieces of armor while the Parasuit is equipped; but it gives its bearer
over 70 defense points and protection against fire, ice, and gas.
There's only two of them in the game: One is in the Nasty Dungeon, the
other is in the Final Dungeon.
Samurai Bow: The Samurai Bows are by far the most powerful bows in the
game - they can do massive amounts of damage to one group of enemies at
a time. Highly recommended gear for robots - your robot will become a
walking war machine with one or two Samurai Bows equipped. You can find
the two Samurai Bows in the Shogun's Palace (in Edo) and the Nasty
Dungeon. Don't lose them!
Gungnir Spear: Same as the Samurai Bows, except that the Gungnir Spear
runs off strength instead of agility. The only one in the game is in the
Nasty Dungeon, although Odin is also known to use one.
Excalibur Sword: Same as the Gungnir Spear, except that it can be used
an unlimited amount of times. It is hiding in the Final Dungeon.
Seven Sword: See article 4.7.4.
Glass Sword: The Glass Sword deals a huge amount of damage to one enemy,
but it can only be used once. The only one in the game is in the Nasty
Hermes and Hecate Shoes: Where the Geta Shoes boost a character's
strength, the Hermes Shoes boost a character's agility and the Hecate
Shoes boost a character's mana. The Hermes Shoes are located in
Dunatis's Cave (in Apollo's World), and the Hecate Shoes are on board
the Bannana Boat (in Edo.)
Nuke Bomb: Same as the Nuke Bomb in FFL I - they do huge amounts of
damage to all enemies. There are two of them in this game - one in the
Nasty Dungeon and one in the Final Dungeon.
Hyper Cannon: The Hyper Cannon kills all of the enemies on the screen
instantly, but it doesn't work on bosses. You can find it in the Nasty
Abacus: This item isn't particularly strong - its only use is to
paralyze enemies, but it is one of the most difficult items to find in
the game. To get it, you must defeat Echigoya (in Edo) and be extremely
lucky. There's only a small chance that Echigoya will drop the Abacus
once he's defeated.