Ich möchte am liebsten alles.

Note

am liebsten (what I like best/ by preference/ if only it were possible)

am liebsten describes my favourite choice. It can be used to talk about my favourite dish, my favourite hobby, my best colour... or to express options that I would like to have, but which are obviously out of question.

Am liebsten esse ich Kuchen. - My favourite food is cake.

Am liebsten gehe ich spazieren. My favourite occupation is going for walks.

Am liebsten würde ich alles essen.(If only I could) I 'd love to eat everything.