imo the best steel sword in the game is the Forgotten Vran Sword you get from killing Dethmold (on Roches path?) in Act III and looting the key that allows you to loot his safe (i love this sword: it freezes enemies and with the next hit you shatter them

) or failing that Caerme which you get the recipe for from decoding the Encrypted Manuscript in Act III
technically Caerme is the better sword but that ignores the effect the Forgotten Vran Swords freeze effect has in actual combat.
the best silver sword is Addan Deith or Zerrikanterment depending on build. Addan Deith comes from a chest during the Gargoyle quest during Act III and Zerrikanterment that can be crafted from a pattern sold by the Mage blacksmith guy in the same act.
the best armor is the Vran Armor you craft in Act 3 that you have to do the 3 act Mystic River chain to do OR the Armor of Ysgioth you can craft it from depending on build
the best gloves, legs, boots are Elder Blood set you can craft from the patterns you get during the Gargoyle quest in Act III though the Mage Trousers you get right at the start of the game from the Magic Suit DLC might be better for a caster build and i've heard there are a pair of "Mage Gloves" hidden in late Act II somewhere.