Diablo 2 does not have 'cheats' per se - here we outline two interesting points inside the game.
The Cow Level:
Successfully complete the game.Then, obtain "Wert's Leg" in Tristram (where you go to rescue Deckhard Cain). Go to the northwest part of the town and search the boy's body. Place both Wert's leg and a Tome of Town Portal in the Horadaric Cube, and it will open a portal to a hidden level filled with polearm carrying cows, including the Cow King. This place is great for finding incredible loot, try it out in the various difficulties [normal, nightmare, hell].
Unlimited imbues and socket equipment
You can have unlimited imbued item - You can keep them and unlimited socketed item without cheating or hex editing. You need 2 computers or a one with 2 simultaneous copies of Diblo 2 running, 2 different characters say a paladin and an amazon.Lets say the Paladin has been granted an imbue award. But he wants 2 objects to be imbued lets say a shield and a scepter. Make a copy of the paladin save game before you do this. Now go to Charsi and imbue the shield. Trade this shield to the amazon for safe keeping. Exit. Copy the backup save game you made earlier over the current one. Trade back your shield, and now you can even have the scepter imbued and get to keep it. So you have unlimited imbues.
The same can be done for socketed equipment.