1. Bots - Yes, including the Slut Bots with the sexy avatar pics and drivel in their Twitter streams.
2. Feeders - people who post literally nothing but links to their blog and blog posts.
3. @ reply spammers - the people (or bots) that @ reply to you with a link to their spammy shit are easily avoided but they never go away.
4. Lack of Tweet Filters - The inability to filter my Twitter experience to remove offensive content like anything about Kanye West, Justin Beiber or any of the moronic Kardashian tribe is annoying and needs to be fixed.
5. Twitter shorthand writing or txtspk. via @dirtymushroom.
6. Check-ins - I use Foursquare every day but you'd never know it by reading my Twitter stream. Why? Because check-ins are noise and I do not take part in them. I wish more people would do the same because I really couldn't give a shit if you just checked in at KFC.
7. Celebrity knobs - People who gushingly tweet at celebs in the hopes that one will someday respond are noise. Noise isn't useful, its lame.
8. Hashtag abusers - #There #is #simply #nothing #gained #by #tweeting #like #this. And its super freaking annoying to look at. Same goes for the ALL CAPS TWEETERS but twice as annoying, at least.
9. Cute tweets - The shitty tweets that include icons, ASCII graphics (they still suck, FYI) or other cutesy crap (I saw one the other day that had a heart between every word) is noise.
10. Any tweet involved Kanye West or Justin Beiber - no explanation needed.
11. Any tweet involving Courtney Love showing off any part of her body - Lady, you're a skanky nasty untouchable mess. Please keep your clothes on, there's not enough eye bleach to go around.
12. Headline tweets that repeat themselves - What's wrong with this tweet? "BREAKING NEWS: Five armed men robbed a Salvation Army bell ringer. Breaking News: Five armed men robbed a Salvation Army bell ringer..."I got it the first time, thanks. Repetition in tweeting is a waste of time and is annoying too.
13. Obtuse replies - Oftentimes I have to go and search my Twitter history to try and figure out what the hell the person is replying to me about. A really short reply that has no reference to the original tweet is dangerously close to noise.
14. Retweeting @ replies to say thanks - Use a DM to say thanks, you're not convincing anybody of anything except that you're a praise junkie.
Update: My buddy, @jmdillon, has this pet peeve to add:
15. Unfollowed Follows - When someone ends up in your stream that you know you didn't follow. How'd that happen? I've had this happen on occasion and, after a WTF? moment, I block them and move on but it is annoying!
16. People who replace the first two letters of words with "Tw" to Twitterize them. Yes, I am guilty of this one on rare occasions. I have kicked my own ass for it already, thankyouverymuch.
17. Rampant retweeting of one person - This is pretty sqaurely aimed at @KennyFlorian and his sidekick acount, @kenfloassistant. Kenny pretty much retweets everything his "assistant" tweets. It has gotten to the point where I'm damned close to unfollowing him because it is so annoying.
Did I forget your peeve? Let me know in the comments below. And you are welcome to follow me on Twitter with the caveat that I don't auto-follow back, you're gonna have to have something of value to get me to follow you back, sorry, I'm a jerk like that. And sorry but there's simply no way I'm following any Dodger fan back, ever.