Going only on DPS, Fighter/Hunter with Deadly Archer (Double Sabers). Brave and Fury stance can be used at the same time. Easy-to-use PA that's good in almost every situation.
Others may disagree but this is what I'd go for. Activate Fury Stance, switch between Brave (most of the time) and Wise (if the boss you're fighting has an interest in someone else and is too mobile to hit in the face), and generally go to town.
I've also seen some nice numbers from Fighter/Gunner using twin daggers and the aerial boost from Gunner, but that works against the Gunner's chain ability more often than not. Twinguns are a nice addition.
Personal favourite is Techer/Fighter or Fighter/Techer, but I'm not awesome enough to have that levelled up highly. Main/sub choice for these relies entirely on what rare weapons I find.