The best weapons are obtained from recruiting the chiefs, after gaining access to Avalonde city in the post game:
-Energy sword: given by chief Claudias, in stonwahl fort.
Energy Hammer: given by chief Sheridan in Rubeus town.
Energy Rod: Given by chief Eragon in Alrare town.
The second best weapons are obtained from the awards:
-Ragnarok (Synthesis a lv 50 weapon)
-Mjolnir (defeat 1200 enemies)
-Holy rod (break 80 pillars)
I found a couple of cursed weapons from hidden rooms in the last 2 dungeons that have a higher attack power, but they put a curse effect on you and I don’t think they’re worth the hassle.
The best armors are obtained from the arena exchange: Celestial armor, and celestial helmet. Or arch fiend mantle, and arch fiend masks. You need to grind a lot of coins for them (6,500 coins each).
The second best armors are the paladin vest, robe, and mail obtained from chests in the final post game dungeon (alternate dimension), and hades helmets, 3 of them are obtained from one of the treasure stores.
Best Equipment
I don’t remember exactly where they are, but I remember that in the last 2 dungeons (normal end and true ending dungeons) that there are hidden rooms where you need to pass through the walls to get to them (you can see them in the mini map), I found them in these rooms but I haven’t found the third cursed weapon.