Currently my Top 5 

1. "text only, no calls" Agents that do not communicate professionally.

2.The "nesses":  Unresponsiveness, rudeness, ineptness for this profession

3. Agents that think they have no value unless they cut their commissions.

4. Flaky buyers or "splinter gathering" buyers that drag out the process.

5. Know it all, stubborn sellers.

Agents who don't READ THE LISTING before calling me with Qs answered IN THE LISTING.
Agents who confuse 'arguing' with 'negiotiating'.
WHINING.
Consumers with attitude due to excessive Z/T/HGTV
Consumers who think their drawn out sob story will help them bypass procedure.
Anyone who tries to get their way by yelling or talking over.
Snowbirds. 3:)

I can sum it up by saying unprofessional, lazy, non-responsive agents. Like Michael Jacobs - I will focus on postive and I find the silver lining. 

That is an area that is best not to visit with my focus, best to focus on what motivates me in this business.

Every business has its stuff.

The higher the count of people, the higher the pile of stuff.

Drama queens push me towards murderous.

Stuff happens.  I prefer to concentrate on the positive rather than negative whenever possible.    

Jack,

Real estate agents who go out of their way to point how lousy other real estate agents are, and how they are God's gift to real estate.  A

and the person you described above will continue to make money every year..... and THAT IRRITATES ME.... 

Agents that can't return calls in a decent timely manner

Lack of communications from other agents

Agents that are rude or unprofessional

Those who don't return phone calls, texts, or emails - often we just move along

Unnecessary drama is the root of most things in this business that can be annoying.

I'm not easily irritated.  I just get a long.

NAR and Zillow.

Unprofessionalism from those who work in the industry.  They are the reason we have such a bad rap with the public.

Dumb agents...

Those that have never read the contract but will argue with you that what they think is correct.

Eve

 parked and reading

 Whiny agents.  

That would surely irritate me. I've often said this would be a great business if it wasn't for the people! Of course, it's also a great business because of the people.

 Unprofessional "professionals" who do not answer their phone.

Jack Lewitz you got to do what is best for your clients - and sometimes, it's okay to override showing instructions, if that do not work.

Great question Jack Lewitz and many interesting answers as well

The other agents.

Rude and people that they think they know it all.  Don't get upset in front of the client.  Let them continue to talk and when they are ready for you to speak do so calmly and with showing that you do have knowledge on the situation.

Both Candice A. Donofrio and Thomas J. Nelson, Realtor took all of my answers - they are saying it like it is Jack Lewitz. 

Agents who don't answer their phones

Just plan old dealing with inconsiderate rude people. Thankfully they're in the minority.

Buyers that are constantly late, and have no respect for our time.

The #1 thing is the sheer number of people out there who have absolutely zero problem with wasting as much of our time as they see fit.  I've run into so many over the past 90 days.

Lack of communication.  Lack of follow-through.

People

Some of the agents that you have to work with.

The others have answered for me.

Agents that don't respond, don't meet the deadlines, expect me to handle informing escrow of their items as well as mine... it's a long list but mostly it's all small stuff and I don't give it much energy.

We have a new automated showing system from the MLS. It is worse than an agent not returning texts.

Many agents have communication issues, I'll never get why. In my experience busy successful agents do answer, those who pretend they are busy~ do not. 

It's often the other agents who cause unnecessary irritation in this business. 

I don't know if the word "irritate" applies, but people tend to make for work

Jack Lewitz Having to work with people. lol Unanswered telephone calls is right up there at the top of the list.

Working with lazy agents

I would worry if the Doctor(actually psychiatrist) or 911 was not answering; there are other homes!

Got an instruction to write up a contract then no sign no explanation.