I like to use:
Thief-So under appreciated...It is the fastest DS and is good for adding on to chains.

Gunner-I usually use the Cat Nip+Trigger Happy tactic...

Songstress(Just Kidding)...Rikku's Machina Maw-I love Vajra and it's the only SDS where one of the girls can revive their extensions

Dresspheres I hate:
Songstress-Bleh!This one sucks!

Lady Luck-I never got this one 'cause I can never beat Shinra.Which is why I hate it.

White Mage-I like the abilities but,NO ATTACK?!?That's why I equip one of my girls with the White Tome so they can use W.Magic and attacks.