Assuming you want to know about the most long lived...
According to Nester (Nester, E. W., Anderson, D. G., Roberts, C. E., Jr., Nester, 2007), bacteria that form endospores such as Bacillus and Clostridium may remain dorman for perhaps 100 years. The text goes on to describe the problems that these types of bacteria pose because they can make their way into laboratories, hospitals, and medical devices. Clostridium genera include those bacteria that cause tetanus, gas gangrene, anthrax, and botulism.
Nester, E. W., Anderson, D. G., Roberts, C. E., Jr., Nester (2007). Microbiology: A human perspective (5th ed.) New York: McGraw-Hill.