I just started with Walgreens and buying only the items I would use that have Register Rewards. Last week I got the following twice:
Complete Eye Solution ($8.98-1.00 Manu coupon=$7.98 and received $8 in Register Rewards (RR)!!) So basically, I made 2 cents everytime! I also got the Celidryn, a joint reliever supplement. It was $10.00 and you received $10.00 in RR. I did this twice for each item throughout the week.
This is a good store to start with cause you can use a manufacture and store coupon and receive rr's all on a single item!