Yanbu. I don't think it's anything to do with 'forum speak' as some have suggested. You either write the correct phrase/word or you don't. You wouldn't write 'should of' on here and then 'should have' in a work email would you? Surely if you know the correct form, you'll use it? I don't always get grammar or punctuation right, but if I've got it wrong and someone corrects me, I'll make sure I get it right in future.
Bought/brought drives me mad.
I agree with what others have said about 'myself'. It's definitely overused and doesn't make people sound clever.
Imply/infer is another one.
I think I'll go and hide in Pedants' Corner......