Title says it all. I started rushing 
for the bonus gold from 
and the power spike it gives, but 
seems to be too good of an item to NOT rush for it's crazy synergy with both passives. Btw, I'm playing her either top or mid, if that's relevent at all.
Depending on your opponent. If you are playing mid against squishy's i would rather buy but if you are laning top against 
, ofc you have to buy :D
Quinn can actually build quite variably, if you find your laning phase is pretty calm, or if you are being pushed under tower, is good 1st.
is nice but the build path kind of sucks for early game unless you have enough to complete it(
/
dont offer much alone), so I prefer 
generally, especially if 1st. Quinns Harrior passive works with lifesteal so having 20% vs 10% is extra sweet.
There is also the typical 
rush, but I would not leave base without having at least 
for supplemental crit chance.
My personal favorite is most unorthodox though, by rushing
first you can almost guarantee a kill with your ultimate combo, and the harass is very real.
For every champion, your build will always be Situational to the game. For Quinn ADC, if your lane is going well you can build for extra damage and a very good early/mid game power spike. If you build this first before your lane opponent it's almost a guaranteed win in all trades.
If your lane is going horribly, you could consider rushing a for lane sustain so you can focus on farming and staying alive.
If your lane opponent is some like 
, 
, or any ADC with wave clear you could rush a to help counter-shove your lane.
But if you are playing Quinn in the Top lane, I most of the time would rush a just so I can duel any top laner and still have sustain to get 200 farm in 20 mins.
Remember, every item you buy should be focused around your Situation.
For top and mid, I usually rush a brutalizer which I later upgrade into ghostblade after a few items. Then, I usually try for a bloodthirster/BoRK depending on their team. At this point, I get a Shivv and upgrade my brutalizer.
