Presenting your personality is precisely why I carefully write a friendly, intriguing and upbeat cover letter for each and every job.
You can't present a culture fit better than by presenting your personality.
I once went to Dublin for a weekend with the sole intention of eating a banana. I returned with a girl to whom I proposed whilst in Dublin and who has now been my wife for over five years.
That says more about me, outside of my skill set and experience, than my CV ever could and works wonders for making me stand out, as well as intriguing whoever may be reading my application.
That is the best thing I have heard in a long time. I can't stop laughing.
Not every hiring manager cares about this, but I will not hire somebody who can't write half a page of text without making egregious spelling, grammar and punctuation errors. I've seen cover letters that, when opened in Word, become a sea of red and green squiggles. It demonstrates a total lack of attention to detail, among other unflattering characteristics.
Sadly, I rule out a LOT of applicants this way.
Really, just demonstrating that you've taken the time to read our website and try to understand what we do scores you a few points in my book. It's one thing to say you're "detail oriented," but quite another to actually demonstrate it by paying attenting to details.