Most people seem to have "Always notify me of replies" on and that is why you're getting spammed.
To turn off go to Profile->Preferences and set "Always notify me of replies" to 'no'
And to 'unwatch' topics go Profile->Topic being watched and mark all followed by "Stop watching the selected topics"
To turn off go to Profile->Preferences and set "Always notify me of replies" to 'no'
And to 'unwatch' topics go Profile->Topic being watched and mark all followed by "Stop watching the selected topics"