So, Optimus VS Crash (almost typed Optimizer, there. OvO)
Right off the bat, going by
this profile's 7-B, and
Crash's, they're both almost completely equal since they scale to actual cities. Speed is disgustingly in Crash's favor (Superhuman VS Supersonic+), so let's just equalize that.
It's down to hax, which I'm willing to give Crash an edge in. And that's because a variety of useful ones, like Aku Aku's temporary invulnerability, possession (before we go on about how Prime is a robot, this was actually shown controlling Nina's robot spider thing and also the semi-robot octopus titan whose name I forgot), time stop/slow, etc. As well as the fact that Crash typically just... uses them almost immediately. Meanwhile, when's the last time Optimus went "lol, screw your soul"? Not really how it goes, at all...
Overall, Crash. Icing on the cake would be his 4-time resurrection in Skylanders.
Edit: Forgot Precognition for Prime, but with the ability taken to it's very best and given that the fight is almost perfectly equal, I doubt it'd help him against time hax.