Introduced apples, pears, peas and probably fast food – for all the soldiers constantly on the move.
Trademarks – having the Emperor on your coins was the start of a trend of potters stamping their products with their name.
Toilets, baths and drains.  Plus the acqueducts to get water to you.
Roads of course, stone buildings, bridges etc.
Calendar with 365 days and leap years.  July and August come from the Emperors.
Currency – coins existed before the Romans came but not used to buy things!? Roman denarii could be used across the whole empire.
Latin words – plumbing comes from word for lead!
 
 
 
 
[http://blog.english-heritage.org.uk/what-did-the-romans-do-for-us/]