Baltimore classification

• I: dsDNA viruses (e.g. Adenoviruses, Herpesviruses, Poxviruses)
• II: ssDNA viruses (+)sense DNA (e.g. Parvoviruses)
• III: dsRNA viruses (e.g. Reoviruses)
• IV: (+)ssRNA viruses (+)sense RNA (e.g. Picornaviruses, Togaviruses)
• V: (-)ssRNA viruses (-)sense RNA (e.g. Orthomyxoviruses, Rhabdoviruses)
• VI: ssRNA-RT viruses (+)sense RNA with DNA intermediate in life-cycle (e.g. Retroviruses)
• VII: dsDNA-RT viruses (e.g. Hepadnaviruses)

Acknowledgement
http://en.wikipedia.org/wiki/Baltimore_classification