Reinforce obviously...
Reinforcement on both weapons and gear is more important than phy / mag attack and phy / mag defense; because they are base values. Obviously you would rather a higher multiplier than a number you just add on to an equation.
Here is an example that proves that:
Magical Attack = (INT Points x Magical reinforce + Magical damage)
Level 98+5 wizard staff, Magical attack 80% (reinforce 0%)
501 x 442.9% + 3434 = 5652.929 (Lowest)
501 x 541.3% + 4091 = 6802.913 (Highest)
Level 98+5 wizard staff, Magical reinforcement 80% (attack 0%)
501 x 479.8% + 3298 = 5701.798 (Lowest)
501 x 586.5% + 3925 = 6863.365 (Highest)
501 is the max INT at 100 (I think, it's what I got when I figured out max STR.. so INT should be the same.)
As you can see, 6863.365 > 6802.913, therefore reinforcement of the weapon is more important than the magical attack itself. (I haven't tested hybrids, but I would assume the same would be true)
source:
http://www.rev6.com/forum/showthread.php?4014-Physical-Magical-Reinforcement-on-Gear.-What-does-it-mean