Comma splicing is the ULTIMATE SIN, whereby two sentences are mashed brutally together using a comma rather than a conjunction. It makes you look illiterate. It really gets on my nerves. For instance, if I'd replaced the full stop between 'illiterate' and 'it' with a comma, that'd be an example. One of the worst cases is the use of 'however' mid-sentence, which is nearly always wrong.

I do not enjoy the over use of acronyms, capital letters, smileys and most of all - jargon.
Tuj] I tried to write your address on the damp pasty but the pen sank into the waterlogged pastry. Fancy a damp steak and Bic doughy object instead?

Jargon is necessary to keep the riff-raff out. One thing that really gets my goat is getting the subjunctive wrong (eg. "if I was" instead of "if I were"). Midge Ure was particularly annoying in this respect.

[Darren] Midge Ure was just annoying, fullstop. Mawkish lyrics, play-by-numbers melodies and the most god-awful moustache that was ever grown.
[Btd] Sorry if my use of smileys is too familiar for your liking :o).
[Tuj] My business is sentence-mashing, however, I think I'm quite artful at it, I've been doing it for ten years. :oP

[penelope] Well, now you have yet another reason to dislike him.

Pen] Overuse of smileys ;o). I like the occasional :o) but too many leaves me :o(. In particular I dislike those gif file ones that are commonly used on chat sites. Yuk.
Darren] With your permission I will keep your quote "Jargon is necessary to keep the riff-raff out" in my little book of worldly advice to pass on to my offspring. It'll also come in handy at work - especially when addressing farmers.

[Darren] Your words did rather leap off the screen. I laughed and assumed you were in jocular mode. However, I must confess to being more intrigued by your pet goat, especially one that tell its subjunctive from its elbow. DO tell us more ...