Sometimes it drives me nuts how passionate software engineers can be about things that have nothing to do with the functionality of their software.

Code aesthetics is one such thing. (Those of you non-programmers out there: yes, believe it or not, this is a big deal to some engineers.) Developers will argue for hours about whether one way or another of writing code is "better," for all sorts of absurdly subjective reasons. Among them:

• "It's more readable." I always find this one kind of funny as it completely begs the question. It's like saying, "I personally prefer the way this one looks because it's better-looking." Of course you think the code is more readable your way; that's why we're arguing!
• "It's more concise." This is another popular one. Interestingly, it is often (though not always) in direct opposition to the preceding point.
• "It's more obvious." This one I actually can sympathize with. However, I do hate it (give me a few more years in the industry and maybe I'll change my mind) when the "more obvious" version of a routine is preferred despite the fact that it's also the "more stupid" version. I only agree with going with the "obvious" approach when the difference between it and an alternative with superior performance (for example) is negligble, or when the "superior" version is incredibly nasty (e.g., uses pointer hacks or some obscure implementation detail to accomplish a goal).

Here are some common examples of aesthetic issues which .NET developers argue about:

// Whether or not to use var for locals.
var puppy = GetPuppy();
Puppy puppy = GetPuppy();

// Whether to put the statement in a one-line block on the same line,
// on the next line, or within braces.
if (someCondition) break;
if (someCondition)
    break;
if (someCondition)
{
    break;
}

// Whether to put the opening brace on the same line or the following line
// after a statement block.
foreach (Kitty k in kitties) {
    k.Purr();
}
foreach (Kitty k in kitties)
{
    k.Purr();
}

// Whether to put constants on the left or right of conditionals.
if (0 == value) { }
if (value == 0) { }

The above are just a few examples. I've got another, which a coworker and I discussed just today (very briefly, thankfully): whether methods that return boolean values (I'm actually on a Java project—can you believe it?) should be phrased in the positive or in the negative.

Well, that's not entirely fair. The truth is that my rule of thumb has basically always been to use a positive phrasing and then negate it from the calling side when necessary. For instance:

public boolean isDone() {
    return someMember.doSomeLogic();
}

// Code elsewhere
if (!someObject.isDone()) {
    doSomething();
}

To me, the above is perfectly reasonable. But I discovered today, to my surprise, that some developers don't think so. In fact, not only did my colleague not like the above (he preferred to call the method isNotDone in the first place), he recalled a little coding exercise he and another colleague performed for a Ruby project some time ago that honestly made me shudder. Apparently, in order to avoid the dreaded ! symbol (gasp!), they actually wrote a module to dynamically generate duck typed methods that would return the opposite result of whatever was being called, e.g.:

if someObject.not.done
    # oh my goodness
end

"Seriously?" I asked him. "Just to avoid having to type '!'?"

Apparently, some people care that much.