I drink 4-5 cups of green tea everyday, some loose leaf and some in bags, decaffeinated after 4pm.
One thing that I read in a great book which I recommend to everyone,
Anti-Cancer: A New Way of Life, is that green tea really needs to be steeped for at least 10 minutes for the tea leaves to let the antioxidants out. Lots of people just put the bag in for a few minutes, that's not enough, and there are plenty of high level scientific research backing the author of Anti-Cancer's suggestion to steep longer.
I put the tea in boiling water and leave it there. After 30 minutes the water can be a little bitter to those who only drink extremely weak tea, but to me it tastes great.
Edit: Another important fact about the antioxidants in green tea: after one hour those antioxidants are not effective any longer. So making a lot of tea an drinking it over the day is not helpful after the first hour or so. Again, this info came from that book.
The book has a lot of great info, but sometimes is a little too emotional for me since its for people dealing with cancer. But the info is top-notch. I've read the book maybe 30 times, just trying to drive all of it into my subconscious.