Vote Which one and why! I personally prefer NLS.
Welp, having never used NLS, I guess I like Hikari? (Totally not a biased decicion ) I like their packaging and the fact that my LPS sells it for the relatively cheap, well that explains a lot.
Doesn't Hikari list fish meal as its first ingredient? I heard that was bad because fish meal has really low nutritional value. NLS usually has something like krill, whole fish, or shrimp in it's first ingredient slot. So I would prefer NLS. However, I like Omega One the best because it's at the same level of quality as NLS and it's more commonly available.
I like hikari and have like the whole line. That said my cories appear to be insanely picky and turn up their noses at all but frozen food and nls medicated pellets so far.