Scanner recommendations for large trucks?

Looking for suggestions on what to buy to read codes for larger trucks. The typical obii scanner isn't good enough to read codes on larger trucks. I don't want the fancy high dollar scanner, but I need to read the codes and have the definition of what they mean. I don't need to be able to change the parameters of the engine or other systems. I have the lap top, but if said suggestion includes laptop, no problem. I hope someone has experience good or bad with some of the scanners one sees on ebay or amazon. I appreciate your help. jc