I realise it's somewhat of a curse, but Vandal Savage's immortality.
Ideally, some form of time manipulation though. More than simple time travel. Being able to speed up, slow down, have irl scum saving, age/youth-en people/things... And simple time travel too though.
I prefer covering up to regular sunscreen. A sarong or two will keep the sun off effectively. I found a few days of sunscreen application while camping got pretty manky.