High gain vocals

[LILFX]

Shure 520DX (Green Bullet) + Fulltone OCD Pedal or Boss HM-2 (Distortion all the way down)

Both sound great.

Exactly this. I've been doing the 520dx through a tube screamer for years now.

[cobascis]

toilet paper tube taped to end of sm57 into a guitar amp.

or, decapitator plug-in by soundtoys is incredible, and useful for everything

[MaggotBrainNY]

I like to use a parallel approach... i.e. one channel with the clean vocal, and a mult of that clean vocal running through a Rat or some other type of distortion pedal (Boss DS-1 is also nice), then blend them with the faders in my DAW. I use a Reamp box for this.The other approach I use is to record the vocals with a mic preamp's input stage jacked, then back it off with the output control (if you have a preamp with this capability), OR daisy chaining 2 channels of the same preamp or 2 different preamps together to achieve the same effect. It's basically just a matter of abusing whatever you have at your disposal. You can crush the front end of just about any piece of gear and get this effect. One of my favorite producers daisy chains a pair of DBX compressors, the 1st with zero compression and the level jacked feeding the 2nd.