PSA: ADC Mains
If the enemy team has an assassin and your teammates can't react fast enough before you die and you need a defensive item:

It gives your team adequate time to peel and damage and the assassin has to back off. It's a great item, keeps your HP up fairly high and gives you the defense you need. Honestly, it's a mage item, but it ain't a bad pick me up on adcs. It's also up 3x more than GA will ever be.
-A fellow ADC main. Yw.
.
is cheaper and way more useful against all sources
mostly defensive with loads of HP, adds some AD and also makes it much easier to kite