Though not "best", IMO by far the most universal weapons are Spirit weapons on the grounds almost no enemies resist them. You can find more optimal weapons, e.g. fire vs ice & ice vs fire, etc., but the Spirit weapons are the most reliable if you want flexibility. There is also a case to be made for the universality for physical weapons, but Elemental damage is nice because it bypasses armor.
I've also just updated the ancient and largely-forgotten "high-class" tables: Hand, Light, 2-Handed, Bow and Off-Hand weapons. The Hand/Light/2-Handed tables are particularly useful as combine and list relevant weapon types.
For the most part I made 12-ish DPS the cut-off (less for Bows), but also listing weaker weapons if they have a utility particularly Stun or Paralysis, or if the weapon is reasonably available early, that puts the "lower limit" down at the Magma Shortsword / Enchanted Vulcan Bow / Lightning Greataxe level.
Level of course plays a significant role, I don't consider Sword of Flames or Sword of Shock to be "high-class", however they are each available from the Travelling Armorer. If you happen upon him at very low level with 3k in your pocket, they are definitely high-class for you, and for several levels.
Warrior- adamantite swords
Cleric - nanocarbon sword, if u joined fighters guild and like to utilize duel, the it may be nanocarbon scalpel
Rogue- dirk of betrayal+ and here there are like 6 similiar fast rogue weapons to choose from
Mage need to switch between 4 diffrent staves, but most often will use Magma greatstaff