Originally Posted by jack
Number 2 is correct.
Number 1 is not correct, as coffee is typically uncountable.
It is possible to use "coffee" as a countable noun when referring to cups of coffee.
This is possible: Who wants coffee? How many coffees should I get? - coffees - meaning cups of coffee
On occasion "coffee" is quantified by a specific or definite number in everyday language. I don't, however, believe that I've heard "some coffees" as it is used in your example sentence. "Some" indicates an indefinite number.
Here's another possibility:
Do you want another coffee? - meaning "another cup of coffee".
It's possible to use the plural form "coffees" if we are speaking about types of coffee.