Honestly, I like all the loot earned weapons. I wouldn't want the weapons given by codes as much, regardless of stats. Imo, if you simply redeem a code, you wouldn't quite have a feeling of accomplishment, or I wouldn't, unless you're very unlucky when looting. For example, when I looted my abyss and silver freeze, I felt accomplished for weeks. And besides, if it's something common, would you really want it as much?
If I had to choose, however, I'd pick thunderspine sword.