Late to the party but...
Final Fantasy VIBest Song Standalone: Terra's pretty good although there's quite a few good tracks so picking an overall one isn't easy.
Worst Song Standalone: Techno de Chocobo, I guess. The fact that I don't really remember it (and it is a Chocobo theme) probably says something
Best Song In Context (ie, song used the best in-game): Forever Rachel. Heartbreaking.
Worst Song In Context: OK is once again the man and conveys my thoughts exactly. Next person who hacks FF6 and kills its random battle theme and replaces it with just the music for the current map (ala Super Laggy RPG) wins a cookie.
Overall Impression of OST: Pretty damn good. There is some forgettable stuff in there, but for the most part, conveys the mood and fits the game to a tee.
Final Rating: 9/10
Wild ARMS XFBest Song Standalone: Wild ARMS games typically have killer battle themes. Non-surprisingly, this applies to XF as well. Tough choice between Blank Easel or Intrude Upon Happiness, but I'll second the elf today.
Worst Song Standalone: On the other hand, WA games tend to do silly themes less well. Into the Soup gets my vote as well.
Best Song In Context (ie, song used the best in-game): Mechanical Dancing Fight. Asgard SMASH.
Worst Song In Context: Nothing is particularly bad, so I'll second Into the Soup again since it's the worst track there.
Overall Impression of OST: To quote Snowfire -
Luckily, if you must pick one track "type" to do right in a strategy RPG, it's the battle music, and XF delivers here, with both variety & strength
. And this tends to matter more to me anyway than other music types, so extra bonus points.
Final Rating: 8/10. A little weaker around tracks that aren't battles, but it's good where it's supposed to be.