This is what we use. At their prices (you get 3 doz of each size per case), it's very cost effective. They are less than 2 miles from my front door so no shipping either!

http://www.basequipment.com/SearchRe...nsive_Search=Y

I like these because they are heavy, not easy to tip and since they are restaurant grade they tend to be easy to clean/disinfect. They are a family run local business so that makes it even nicer to buy from them.