Heatwave gets better. He has quite an arc over the series - the other characters more or less do, too - and you see his heart more and more even if he's still grumpypants. <3 Also Mark Hamill voices the Chief's wandering brother and it is a DELIGHT. Also any episode where Bumblebee shows up to visit. And Optimus! <3

Kade either gets better or easier to ignore, I'm not sure which. XD