That really depends on a few things... How much "extra" are you talking? Who are your favorite characters? How much do you like complex transformations? If you're talking a large chunk of change, like $400+, you would do well to spend it all on MP-44. He is absolutely fantastic and looks just like Prime from the cartoon. MP-36 is another can't miss buy. He's about $200 or so, but again, looks just like Megatron from the 80s show! Well, aside from his wonky backpack... But really, most of the newer stuff is great, most of the older stuff is too, so it's all down to price and preference.