1) Fast-Food Workers: Chances are, they're making much less money than you are, and they most likely have to deal with a lot more of the public than you do every day -- the good, the bad, and the ugly. If they're a little grumpy, there's probably a good reason for it. Maybe they just got cursed at because their burger has pickles when they specifically said "No pickles." Maybe the fries are cold -- they didn't make the fries, it's not their fault. Cut them some slack!
2) IRS Auditors: If you should ever be so "fortunate" as to have to undergo an IRS audit, don't take it out on the poor guy or lady conducting the audit. It is not a personal vendetta against you. They know you; they're not out to destroy your life. They're just doing what they get paid to do.
3) Referees/Umpires/Other Sporting Officials: A sporting official's job is to call it as they see it. Most of the time they get it right. Sometimes they get it wrong. This does not make them terrible people. It makes them human. Have a little understanding, and let them be human. You'd probably be hard-pressed to do as well yourself.
4) Police/Law Enforcement: Too many people either fear or hate "cops." In most cases, this is fear and hatred that's unfounded. Granted, there's a small minority of individuals in the law enforcement community who have abused their power and given good reason for people to hate them. But this is not the norm. Chances are, if you're afraid of the cops , it's because you're doing something wrong and you don't want to get caught. If you're not doing anything wrong, you don't have anything to worry about.
5) Lawyers: This is another case where a few bad ones give the multitude of good ones a bad name. I fully realize that, like some of the jobs on this list, lawyers are typically well-paid for their work. But that shouldn't give us the right to hate them for it. While it's often perceived to be one of the "glamor jobs", lawyers do a lot of drudge work that most of us wouldn't want to do, no matter what we were getting paid for it. It's not all Law And Order and Matlock. A lot of it is dull and solitary work. A good lawyer earns the money he or she makes. Don't take it out on a few of them who rake in the cash as a reward for their dishonesty.
6) Car Salesmen: Confession -- I am among the legion of folks who dislike car salesmen. And yet, I know several of them personally. Buying or selling a car is a very important decision. One that I would prefer to make for myself. But a car salesman's job is to steer you in the direction that he or she would like you to go. To sell you that car that's been languishing on the lot for far too long. The newer, more expensive one that just arrived -- that will get him or her a bigger commission. In truth, car salesmen are no different than any other kind of salesmen, whether it be the computer salesman at Best Buy, the furniture saleslady at Badcock's, or what have you. The guy wants to sell you a car, not to make you second-guess your (or his or her) decision for the next four or five years, but because he or she wants to get paid this week. They are trying to put food on the table just like anyone else. And with all that has gone down in the automotive industry in the past few years, it's getting harder and harder for them to do their jobs, which is selling. I'm preaching to myself here as much as anybody, but here goes: Give them a break. And I'll try to, too.
7) Auto Mechanics: Like other jobs on this list, auto mechanics' reputations in general have been sullied by the ones (admittedly, more than just a small minority of them) who are dishonest, unethical, and downright cheats! I, like you probably have been at some point, have been burned on more than one occasion by dastardly auto mechanics who told me I needed something that I probably didn't need, paid them an exorbitant amount of money to fix the problem, only to find that it was actually another problem all along, one "amazingly" not related at all to the one I've already paid for. While there are a lot of dishonest auto mechanics out there, and I may continue to naturally distrust them in general, I do realize that there are many, many honest auto mechanics out there who work hard, do a good job (much better than I could ever do!), and can and should be trusted. I have a guy who does my car repairs now that I trust is among that latter group.
8) Busboys (or Busgirls): I held this job throughout my college years at a local seafood restaurant, not because I wanted to, but because it was a steady job and the hours were always at night (and all my classes were during the day). The pay was lousy, the work was thankless (except for the occasional "thank you" from the nicer waitresses who appreciated that we were doing all we could to get their tables ready for another group of guests), and no, we did not get tips. After hours, we effectively became the janitors of the place (another thankless job!), having to sweep, mop, and wipe down everything in the dining room areas.
9) Truck Drivers: Being away from home and family for long stretches of time. Being on the job 24/7 but only getting paid by the number of miles that you drive. Being cursed at, given the finger, or conversely, begged upon by minivans full of kids to honk the horn when you're just trying to do your job. Sound like fun to you? Not to me, either. But without these guys and ladies, the shelves of our favorite stores would be empty; our restaurants would close down for lack of food to serve; that birthday gift you ordered for your brother online would never arrive. Without truck drivers, we wouldn't have most of the things we enjoy everyday. Think about that next time you grumble because that 18-wheeler won't get out of your way so you can get to the nearest Starbucks for your morning cup of Joe (which was probably delivered by a truck driver not that long ago).
10) Call Center Reps/Customer Service Reps/Telemarketers: Many people don't choose to do these jobs. Often, desperation forces them to take them because no one else will. These jobs often don't pay very well, especially as compared to the stress level that's involved in performing them well. But somebody's got to do it, right? Call center and customer service reps and telemarketers probably take more crap than anybody else, especially since the anonymity of being heard and not seen emboldens many people. Folks will say many things over the phone that they would never say to another person's face. And yet, for the person on the other end of the line, getting paid very little to do so much, they still reap the "benefits" of the customer's fury. And that's not fair. I am as guilty of this as anyone, but it's still not right. Speak into their ears the same way as you would if you could look into their eyes. They're just doing their jobs...