The best floaters out there are the Ibanez Edge, Lo Pro Edge, Edge Pro, Original Floyd Rose, Schaller, or Gotoh. (do not confuse "Original Floyd Rose" with the many crappy licensed far east imports)
The Original Floyd Rose is hardened steel and will have a "brighter" tone than any of the others (die cast). Wither or not this is good or bad can debated elsewhere.
The Ibanez models listed above are the only ones you should consider from Ibanez. Furthermore the original Edge and Lo Pro use locking pivot studs for even better tuning stability. The following Ibanez models Lo TRS, Lo TRS II, Edge Pro II, and Edge Pro III are not recommended.
The Original Floyd Rose and the original Ibanez Edge are considered to have the best "flutter" ability, and some argue the best "feel". Both Steve Vai and Joe Satriani still use the original Edge bridge.
I personally prefer the Original Floyd Rose and the Ibanez Lo Pro, but have used the original Edge, Schaller and Edge Pro. I am not suggesting one over the other, only offering up what my experience has been. However, if you are unfamiliar with all the models and need a solid recommendation, go with the OFR or Schaller. (Floyd "brighter", Schaller "warmer")
Hope that helps