Here's a few attack/balance combos I've personally had fun with:
Phoenix Wing 5-60R
(Great mix of speed, smash attack, and consistency.)
Courage Dran 3-60LR
(Low and aggro. Can steal wins from heavier blades with good launches.)
Impact Drake 7-60L
(Lots of repeated contact. Feels different from standard Rush attackers.)
Whale Wave 5-60P
(Massive KO potential. One clean hit can end a match instantly.)
Keel Shark 3-60LF
(Fun glass-cannon attacker. Either wins quickly or explodes trying.)
Cobalt Dragoon 5-60C
(Very active movement pattern. Creates weird angles that catch people off-guard.)
Dark Perseus 7-60GP
(Hits hard enough to threaten attack types while still having decent stamina.)
Impact Drake 7-60L would also be a good sleeper combo. A lot of people immediately slap R or LR on it but L creates some nasty angled hits and can keep Drake active throughout the match. Certainly more fun than the standard "launch hard and pray" attack setup
Akasumi