I would start crafting the ones you play the most already that are possible to open packs, then you can de the non-golden ones for more dust to make more goldens! If you did what i mentioned thats another 1200 dust towards another golden one. Personally i like doing this because its a 400 dust refund to make any one you already have. you can make 4 goldens off the dust you have if you do that and have 400 more dust towards another one.
I would make the following
Favorite class legendary if you play it
Those would be my top 4 if you do not have any of them golden yet.