Depends on your budget, but IMHO I'd say Argent Protector. Good stats for all the hybrids that can wield it, AC, and unlike Reaver it's Magic, so it can hurt certain enemies that Reaver cannot.
Personally though, starting at 50 I would consider this:
https://wiki.project1999.com/Zealot%...arnadine_Sword
The ratio is slightly better at 50 than the numbers show because of Bonus damage, and the proc is good for health upkeep in combat. It's a good placeholder until epic or a quested PoSky sword, or, even better, have it as a swap to trigger Soul Bond, then switch back to Argent Protector or Reaver to maintain an optimal ratio with life drain on the side.