Para mi vs Personalmente

Hola Jamie,

not in this case because the verb that follows is "preferí" (yo preferí). 

We can't say:

Para mí preferí...

because it is referring to the same person "yo".

If the sentence was different, with a different subject,  for example:

Para mí, la actuación del trapecio fue la mejor.

Here there is a different subject; here it would be correct.

Saludos

Inma