Using "i < 5" would be the form most people would expect to see on a for loop based on common usage. There is nothing wrong of course with "i != 5" or "i <= 5" (expect they'll give different loop counts) but if I see either of those forms I have to stop and think because it's not the most common form.
So I would always write "i < 5" unless there was a strong reason to do otherwise
