From my staples agent I am able to get the best price for what I want. And the other part that is best is the deals they does for a reward credit when you buy certain paper. So not only am I getting a great deal on paper I and getting a rebate offer.
I've used Staples Multipurpose paper for all my general laser print needs. Good medium grade quality in bright white color. When I want to print more important documents I choose Staples heavier laser and inkjet "printing paper" at 24lb with the same 92 brightness. Price is great -- watch for discounts regularly offered.