What is your "go to" fight (s)?
None of that "fighting for position" shit, just a straight out fucking brutal fight!
I'm picking Wand/Rampage 1 OR Hendo/Shogun.
You?
One of the old NHB bare knuckle fights in Brazil. Off the top of my head
Mark Kerr vs. Fabio Gurgel
http://www.youtube.com/watch?v=fhbFkSKc8uo
Melvin Manhoef 
Anything with Wanderlei?
Shogun Hendo
Don Frye vs Ken Shamrock
BJ vs Stevenson
Frye/sexyama 
Shogun vs Rampage, Jeremy Stephens vs Estevan Payan, and Rustam Khabilov vs Vince Pincel. Those are some of the most brutal IMO.
Liddell vs Pele IVC 6
Watching those two trade nut shots back and forth was brutal!!!!
Wanderlei vs Fujita
Don Frye vs Ken Shamrock
BJ vs Stevenson
I had a friend around a few weeks ago, I put on the Stann v Wanderlei fight. Awesome!
Jones shogun
Riggs doerksen
Penn uno
Rampage wandy 1 2 or 3
Carwin mir
manhoef cyborg
bispingpokedmybrowneye - Frye/sexyama
Takayama?
Put on the wanderlei special ppv. Lots of good violence in there
Nick Diaz vs gomi
diaz vs daley
Some Wanderlei Pride fights, and the Jardine fight. That schoolyard choke will forever entertain.
Oh, I almost forgot Fedor vs Sylvia. If I saw a beatdown like that happen in the street I'd run from the pudgy Russian guy.
I'm sure theres better examples but the first one that usually comes to mind for a thread like this is Kharitonov vs Schilt. Not so much the ferocity of the fight but the way Schilt (an enormous, great kickboxer, gets mounted with his arms pinned down under Kharitonov's knees and then he just takes donkey kong hammer fist after donkey kong hammer fist until they called the fight because the audience see's all the blood.
The way Schilt was gurgling and screaming, trying his hardest to get up and out of that position while just eating one bomb after another is a crazy sight. One of my favorites to show to people who havent watched MMA before and think they're all gay pussies who just roll around and grab each other.