There is no best coax, just the best for what you need it to do, or the best you can afford that will get the job done, they each have pros & cons,
real rg213 is medium loss & tough as old boots, how i use my 213 it needs to be though,
bend it tread on it run over it with car throw it around yard while i mow the grass bury it leave it in sun snow year after year at least 18 of them,
I was going to change it before i checked the match & loss against a new role of 213,
it still works with good vswr & normal losses, still clean & shiney copper inside,
I also use coax with half the loss of 213 & better shielding for vhf/uhf but its no good for my 27mhz setup because i can't abuse it like 213,
I won't use foam coax outside, its far too fragile,
my buddies mini8 shorted out in the sun due to not having enough support points,
the cb shop stuff bleaches in sun & goes brittle,
what's best for you is probably not best for me.