It really annoys me when people whisper 'hello' or something equally innocuous. Obviously sometimes it's because they've been perving your profile and forgotten to switch back to chat to room, but I just ignore whispered greetings - what is the point of it? I don't disable whispers but do prefer to be asked first.
When my name used to be dp_red (dp are my initials, red was my ex-wife), I used to get really annoyed by single blokes whispering me to ask if I like double penetration. I'd inform them that I'm a 6ft tall Black Country bloke with a beard you could lose a badger in and ask them if they were still interested. For some reason, none ever were.