I'm tending to agree more with Carados on a lot of these. Really the only thing I'm commenting on is how useless your Garen becomes. Sure he is a pubstomper early game, but if you just build tank and zero damage other than a sunfire and a mediocre Judgement with no dmg/crit, he becomes pretty ignorable and is just a Silence running around in circles with his head cut off. Not to mention a tank that KS's the damage dealing carries. As a tank, you should be feeding your carry kills, not stealing them from him/her.
I build this:
Ghost/Exhaust
Doran Shield or Boots of Speed + pots
Brutalizer
Boots of Swiftness
Sunfire Cape
Ghostblade
Force of Nature
Infinity edge
Black Cleaver (Normally, but I may get another defense item if needed. Games rarely last this long.)
I'm against narrow minded builds, but Garen is my exception. This build works against just about anyone.
Also, I tend to level abilities in this order - Q > E > Q > W > E > R. Then level both Q and E together getting W last (R at 6, 11 and 16 of course). W is a bit better since the last Garen update. Decisive Strike does insane damage early game. More than Judgement and it's instant damage. Also the Silence means they can't immediately Flash away. It's gotten me FB many times.