All from Snatch:
"Heavy is good. Heavy is reliable. If it doesn't shoot, you can hit him with it"
-Boris the Blade
"It was two minutes five minutes ago!"
-Turkish
"What's a gun doing in your trousers?"
"It's for protection."
"Protection from what? Ze Germans?"
-Turkish and Tommy
All from Lock, Stock and Two Smoking Barrels:
"The British Empire was founded on cups of tea."
-Eddie
"We grow copious amounts of weed and you're carrying a wasted girl and a bag of fertilizer. You don't look like your average horti-fucking-culturalist, do you?"
-Some guy
"Also, I think knives are a good idea. Big fuck-off shiny ones."
"Is there something we should know about your past?"
-Soap and Eddie
All from Kiss, Kiss, Bang Bang (my favourite movie of all time and vastly underrated):
"I feel badly about it"
"Bad. Badly is an adverb, so to say you feel badly would be saying that the mechanism which allows you to feel is broken. "
[... later on in film...]
"Oh, and sleep badly. Hesitate to call."
"Bad"
"Excuse me?"
"Sleep bad, otherwise it means the mechanism by which you - "
"No fuckhead, who taught you grammar?"
[RDJ's character accidentally shoots captive in the head while bluffing with Russian Roulette]
"Why did you do that?"
"I only put one round in, there was like an 8% chance!"
"Eight? Who taught you math?"
[later on]
"You, stop multiplying."
"But what do I know, I'm a bear. I bite the heads off fish!"
And finally:
"The grave loomed before him like a big hole in the ground."
- from a Douglas Adams book, can't remember where.