Bought a $12 silicone drain snake instead of calling a plumber, and it pulled out a hair clump the size of a small animal | Buy It or Cry Later - Vivisector
My bathroom sink drain was running slow for like 3 weeks and I kept putting off dealing with it. Finally grabbed one of those cheap plastic zip strip things from the hardware store for about 6 bucks. Pulled out this nasty black gunk that looked like a dead mouse, I almost threw up. Ran hot water after and the drain has been perfect for months now. Best money I ever spent honestly. Way better than dumping a bottle of draino down there and hoping for the best.