Being an amateur storm tracker, I don't know of any definitive sites that list them all in totality. However, you can start here:
http://www.spc.noaa.gov/climo/
Which is the NOAA storm prediction center site where you can run searches by date. Additionally, you can look here:
http://www.spc.noaa.gov/climo/torn/monthlytornstats.html
Which lists tornadoes by month / year and also provides maps of the deadly ones.
Finally, you can take a look here:
http://www.spc.noaa.gov/climo/torn/2005deadlytorn.html#Total
Which displays a map of all of the deadly tornadoes of 2005 on a map.
Not exactly what you are looking for, but hopefully a start.