BEASTIES!!
When the Beast Wars toys first came out (so before the cartoon was out), the toy bios and comic portrayed them as being continuations of the Autobots and Decepticons - i.e. that Optimus Primal was Optimus Prime in a new form and Megatron was G1 Megatron etc. But then when Vancouver based Mainframe Entertainment made the cartoon, they threw that out the window and created a new canonical premise where the Maximals and Predacons were NOT the Autobots and Decepticons with new modes, but rather the descendants of the Autobots and Decepticons - centuries after the Autobot-Decepticon "Great War" had ended and the old factions were officially disbanded.
I think Beasties Megatron is a great character; whereas G1 Megatron was more inclined to use direct force, BW Megtron used guile/deception and played everyone (allies and enemies) off each other in order to obtain his goals. As Beasties Megatron once adaptly said,
"Deception is the better part of valour." 