Here is the official thread for any discontinued (or possibly discontinued flavors) of Monster.
What is your favorite discontinued flavor (or flavors), and what did they taste like?
I'll start first. My favorite discontinued (at least I think it's been discontinued here in the US) is Monster Reserve Watermelon. It's sweeter and overall tastier than Ultra Watermelon is and I would kill to get my hands on a can of Reserve Watermelon as that one was the better of the 2 watermelon flavors the company has released in my (possibly unpopular) opinion. Ultra Watermelon doesn't have as strong of a taste as Reserve Watermelon did, which I find disappointing.