As an English major, the answer to this is obviously going to be "Hey guys, use a bit more grammar from time to time. Please?"
The problem is I don't ask for constant proper grammar or spelling. I have no hate for folks who mind concluding sentences with prepositions, or making obscure but functional use of sentence fragments. It honestly depends entirely on how well it works in application.
"I was left without enough solid ground to stand on. Oh crap." Those are both incorrect. The former having ended on a preposition, and the latter being a sentence fragment. Regardless of the fact that there are errors, I see no problems with that type of incorrect-usage. It's stylistic, but still very easily comprehensible.
The problem is whenever even the minimum amount of effort is applied. Phrases like "c u wen u gt 2 teh place w/ 3d n mal w/ my $" is so much harder to read than "See you when you get to the place with 3D and Mal with my money." I'm not asking that everyone have the proper spelling for "onomatopoeia" or "silhouette", or that everyone follows the basic grammatical intricacies of period placement around quotation marks.
I do, however, want people to put breaks in multi-paragraph writing so that I can figure out where thoughts end and begin. I expect writers to observe even the most minor of grammatical concepts to make thoughts even remotely clear. I also hope that people don't spell "you" and "see" out of laziness rather than just mistaken spellings.
Really though, it's about application. If I have to edit your post just to read it, you need to work a little more on grammar and/or spelling. If I need to take a deep breath and give up on your writing because it's near-incomprehensible or just plain difficult to read, then I'll just stop.
I guess all I ask is a minimum amount of effort.
EDIT
ssgt splatter said:
as long as it makes sense, who the hell cares
For stuff like this, I guess it's all a personal taste thing. I would like to point out that fully functional and proper grammar has its place. I wouldn't advise writing with the "Who the hell cares?" mentality when you're writing an essay or filling out your resume. Proper grammar and spelling does imply both professionalism and effort. When dealing with works to be judged by your peers and used by individuals, then you want to appear professionally.
Granted, on a forum, "Who the hell cares?" doesn't have to be a bad thing. Though I will say that laughing at someone who makes a request to adjust your grammar would be rude regardless. Maybe it's rude to ask in the first place, but hatred begets more hatred.
No need to be rude, just say "No." and move on.