Pills=no.
that's my 2 cents. i tend to be a purist when it comes to food and health, and i just don't get the whole practice of discovering something beneficial and turning it into a pill. I think part of the reason that green tea is so beneficial a part of those eastern culture where it is widely consumed is that it is a part of their lifestyle.
Pure simple green tea steeped in water and drank several times throughout the day along with a diet high in vegetables etc. is not the same as popping a so called green tea pill and drinking your diet coke or whatever typical american foods we here tend to ingest. Not saying you do that, that's just a generalization of our country.
that aside, i have found that you need to find a good quality green tea to really decide that you like the taste. i've met a few people who say they dislike green tea, but they've only tried a crappy brand.
loose leaf would give you the best flavor, but that can usually only be found at specialty stores, asian supermarkets or healthfood stores.
as far as tea bags go, i prefer trader joes or newmans own. both are sold in a 40 pack for @ 3$. and taste pretty good.