Ultima IV/YMMV


 * Character Tiers: The Paladin class gets access to the best armor, decent magic, and can use every weapon except the wand. The Shepherd... not so much.
 * Even Better Sequel: Along with Ultima VII, this is usually regarded as the best game in the entire series, not only further developing the gameplay mechanics and storyline of the previous three entries, but attempting something completely different to the "band of heroes defeat a bad guy" storyline used by most RPGs until that point.
 * Game-Breaker: Use of the secret entrance to Hythloth inside Castle Britannia, followed by the Exit spell, allows you to quickly access Hythloth's main overworld entrance, which has a very useful magic orb nearby which boosts all three of your stats by five. It likely kills you and your party in the process, but you're transported right back to Lord British in Castle Britannia. Rinse and repeat to quickly max out your stats.
 * Growing the Beard: This is the game that established most of what the series is known for today, leaving behind the Early Installment Weirdness, introducting the concept of the Avatar and the ensuing moral questions, and so on.
 * Memetic Mutation: "Thou hast lost an eighth!" The phrase even made its way into Doom, of all games.