Sol and those double hit spheres like hallowed skull, sinister orb, lexidia. Great in Arena with a leader like Ultor or Zurg.
If you the kind that like to OTK, I think Amahno and havoc/geldite is good
For long battles like raid, definitely Sol Legwand or Malice haha.
Those GGS like Batootha, are good too, depending who you use them on. Batootha is great for high SBB attackers I think, alongside some flag flower jk, you don't like to live on the edge, so heavenly bud :evil: jk jk, lol. Steeple rose is good too for those who want to play it safe (you can only have 1 btw if you want to lay low, keep that in mind) so flower bud is the next. Want to spark nicely, but at the same time you want the sparks to do some good amount of damage.
Overall though, I personally like to Sol slap everyone, haha. My healers, they either get Drevas ( the HP boost with immunity to status ailments - i think that's the sphere) and Sol or refined gem or guardian cloak (the 330% def boost when gp is below 1/2 - might be 25% though, not sure) or with refined gem.
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Looks like there's an update coming our way from global tonight... Hope nothing get's patched !
http://www.reddit.com/r/bravefrontier/comments/2zbhmu/maintenance_later_tonight_any_predictions/