I believe the best leveling strat is to start with pvp gear, if you've kept up with that grind, so that you have decent gear to start running hard mode flash points.
Otherwise, this is my recollection from pre 1.2:
Tionese
PVP Gear (now maybe recruit?)
Columi/Battle Master
Rakata
Here's a nice list of what FPs have gear drops. I remember being able to get rakata from HM FPs, but according to this, since 1.2 they moved those drops:
http://dulfy.net/2012/01/15/hardmode-flashpoint-drops-empire/The one rakata that drops from a FP is the chest from Lost Island. The only other way to get that piece is to run HM SOA. From my experience with running HM SOA, I think the FP is going to be the better way to get that piece. But I've never run Lost Island, so I might be wrong!