Seriously, grmpffff! (<- held back laugh), only thing I know is that just Ha Ha or HaHaHa, can be delivered in a very sarcastic way too (go @milanfahrnholz, insert a Nelson Muntz meme), so caution is advised.
And Hi Hi Hi is for girlies.
And Ho ho ho for Santa
Yes, the question seems to be weird and not important.
But sometimes you have to write down laughter and that is not as trivial as it seems. For example in English you can write “He”, but in German that would be an exclamation. In German “hi” is a (short) laughter while in English one could read it as a greeting. Another question is: How do you write “ha ha”? In camel case: “Ha Ha” or in small case: “ha ha”? The latter question might not be important in an informal forum post, but for example in a novel.
So …
… is “hi hi hi” actually a laughter for girlies in English? Don’t you read it as “hey, hey, hey”?
There’s a ‘Ha-Ha Road’ near London that caught my eye once. This is why it’s called that - because it’s near a ha-ha. Haha.
I’m a bit late to this conversation but I use a number of variants for different purposes:
Haha (no exclamation mark) - deadpan or acknowledgement laugh.
Haha! - surprised laugh.
Ha! - short, snappy laugh.
Heheh - small laugh.
Tee hee - cute or cheeky laugh.
Fnar - laughing at something rude, or innuendo, as referenced by Milan.
Baaaaaaaaah! -