I would say drink as much as you're comfortable with. This is like asking "should we all be drinking 8 cups of water a day?"

Just the only thing to keep in mind that it is a mild diuretic, so don't be surprised if you drink a ton and consequently have to pee a ton more than before.

I drink 2-3 cups of various tea. Usually Dong Quai, Chai, and Earl Grey. 

I drink tons, but in the evenings I only brew the caffeine-free kind.

Drinking too much green tea can be really bad for you.  However, it will take 6-10 cups a day to do any significant damage.

"A review of recent research
found that when people ingest too much green tea -- especially in
supplement form -- they run the risk of developing liver or kidney
damage. Though the polyphenols in tea are beneficial in moderate doses,
they can be toxic at high levels. Green tea supplements can contain 50
times more polyphenols than a single cup of green tea."

http://www.thatsfit.com/2007/05/07/how-much-green-tea-is-too-much/

"Tea plant accumulates nutritions such as aluminium, manganese and fluoride from
soil and water. These minerals can be harmful when consumed in large amounts over
many years.

A 2005 study conducted by Dr. Michael Whyte from Washington University
raised concerns about the high fluoride content in instant iced tea."

http://www.amazing-green-tea.com/drinking-too-much-green-tea.html

"Drinking high levels of fluoride can cause bone-forming cells to lay
down extra skeletal tissue, which increases bone density. At the same
time, it also increases bone brittleness that can result in a disease
known as skeletal fluorosis. So while bones are more dense, they are also
more brittle. Skeletal fluorosis can produce:

Bone, muscle and joint pain
Calcification of ligaments
Bone spurs
Fused vertebrae
Difficulty moving joints

Says Dr. Whyte, "When fluoride gets into your bones, it stays there
for years, and there is no established treatment for skeletal fluorosis,
No one knows if you can fully recover from it." In other words, fluoride
accumulates in your body.

And according to one estimate, the first phase of skeletal fluorosis
could easily develop in as few as five years if a person were to consume
the amount of fluoride found in three or four cups of green tea every
day. That's because studies have shown that most green teas have more
fluoride than the EPA's safe limit for drinking water, which is 4 parts
per million (ppm).

Fluoride can also affect the thyroid. Specifically, it suppresses thyroid
function, leading to hypothyroidism. This is a well-known fact, as, ironically,
the amount of fluoride in a typical cup of tea is actually much higher
than amounts that were used decades ago as medication for hyperthyroidism,
to reduce thyroid activity."

http://www.sixwise.com/newsletters/05/02/22/why-green-tea-would-be-healthy-except-for-this-one-dangerous-issue-004.htm

last week i was so tired & since i don't drink coffee, i had 11.5 cups of it that day. 

I think what pops into everyones mind is one "cup" of tea isn't neccesarily 8 ounces, but how many times they finish drinking out of there tea cup. I think 2 is just fine, one for breakfast (caffeinated) and one at night after dinner/dessert to get rid of the greasy feeling. 3 cups max... anything more than that I feel can be just as bad as coffee.

hehe i drink soo much of green tea. it's yummy

Three seems like a good number. :) I'd love to be able to. I'm hoping that soon we'll get a tea kettle, and then we'll be able to make tea more often. I prefer not to use instant. But, that's just me. :p

It's kind of pathetic that we have such little money for extras that we can't even afford an $8 tea kettle! Lol! But, soon.

ten or more

I would if there were more hours in the day >:
I drink about 5-6

I love decaffeinated Green Tea. But I read recently that regardless of how much you drink, not all the benefits actually get to your system the way you like.  But you can fix that simply by adding a lemon to it (go figure).
So drink away, just don't forget the lemon...otherwise, the benefits are about as good as drinking flavored water.

Green tea is good for helping to digest fat. I drink green tea after I eat meat with fat in it.