Suppressing "reopen windows" dialog when restarting a crashed program in Mountain Lion
defaults write com.apple.CrashReporter DialogType none (or the option in Secrets) disables crash report dialogs but not the dialogs shown when reopening crashed applications.

Disabling Resume would remove them though. You can either check "Close windows when quitting an application" in the General preference pane or disable it in individual applications with defaults write -app "Application Name" NSQuitAlwaysKeepsWindows -bool false.