I used to be all assaults all the time. The bigger the better, who cares about speed?
I still lean that way, but I've mellowed a bit. Now my favorite range is low-assault to high-heavy 4/6 movers. BattleMaster, Awesome-9Ma, Black Knight Night Gyr, Nova Cat, Marauder, Warhammer, etc. Some bleed-over into heavier 4/6 movers like the Banshee, Berserker, or Kingfisher, or 5/8 designs like the Gargoyle, Mad Cat, Falconer, or Neanderthal.