Not an archetype, but I've been really happy getting Arcane Deed and Flamboyant Arcana on my Magus. The constant level to precision damage is a wonderful boost. (Fun fact, as written the Swashbuckler's precise strike only requires that you don't attack with a weapon or use a shield other than a buckler. You can still attack with a spell.) I don't parry & riposte often, as the arcane pool doesn't recharge as easily as panache, but it is one more layer onto your defenses.
Also, I wonder if the Bloodrager shouldn't move up a tier. They've got a better spell list now, and the bloodline selections open up even more flexibility. They also have a reason to not dump Cha, and enough skill points to do something useful even if they do dump Int.
Worth noting: The Primalist archetype is nothing but a straight improvement over a vanilla barbarian. You give up 1 HP a level (d10 instead of d12), and trap sense, and get bloodlines, spells, blood sanctuary, and can still get as many rage powers as before (although you do need to wait 4 levels to pick two, instead of picking one every 2 levels).
I appreciate the Bolt Ace for gunslinger's too. It lets a player use the class even when you have an anti-firearm GM.