I read an article back in August on socialmediatoday.com about 8 habits that could potentially get you unfollowed or piss off your followers enough that they will pay less attention to your tweets. I have the link for the original piece I read below but here is the list (some reworded into more terms that are clearer than what is in the list.) from least annoying habit to most annoying habit. Check them out and let me know if you agree or not or if you have other habits that you thhink should make the list:
8. Constant Tweeting about your own business (sales, promos, etc)
7. Tweeting about private matters that are not pertinent to all of your followers.
6. Partial or cryptic @replies
5. Tweets that are links only
4. Tweeting about sweepstakes, promos and contests or viral marketing messages
3. Automated direct messages
2. tweeting to all of your followers a thank you for a compliment
1. Discussing politics, sex or religion (unless that is what your twitter feed is all about)