Ozzy - Crazy Train
Mercyful Fate - Nightmare
There is a track on "A Sucked Orange" by Nurse With Wound that is pretty much only maniacal laughter layered on top of other maniacal laughter.

I'm sure more will come to mind soon.

The Spectral Presence- Is This a Test?

BTW I gotta upload that EP sometime.

bob dylan starts giggling at his own words on all i really want to do, and at the beggining of bob dylan's 115th dream. and there is also that creepy laughing in the modest mouse song alone down there, thats all i can think off the top

you mean a spontaneous, "real" laughter or a "fake" one on purpose for the song.

It really doesn't matter.

oh, ok.

Afrirampo - Natsu Ga Kita

they laugh so hard in that song. It's actually the only Afrirampo song I like, and just because of the laughter.

Kyra was a member of Thee Headcoatees.
On her solo album on Vinyl Japan (Here I Am, I Always Am), among Billy Childish songs, Electric Eels, Jacques Brel and Captain Beefheart covers is a track called Laughing Song.
It's pretty short, 100% laughing-in-tune-if-she-can, and it ends in real laughter, with a mike falling to the ground. One I do enjoy.

Feel Good Inc. - The Gorillaz
I Am The Walrus- The Beatles

Zu+Teatro degli Orrori - "Fallo!"

the beatles - i am the walrus hee hee hee ha ha ha
the beatles - ob-la-di, ob-la-da
the beatles - hey bulldog laughing during solo mostly paul
the beatles - yellow submarine - laughing before last chorus
the beatles - two of us george laughing at john in beginning
the beatles - within you without you some audible laughter at beginning, or is that the ending? of the long version

lots of other ones i'm forgettting i'm sure

bob dylan - i shall be free no. 10
bob dylan - bob dylan's 115th dream
johnny cash - a boy named sue
pink floyd - brain damage laughing in intro and in bridge
motley crue - girls, girls, girls laughing amid the motorcycle noises in beginning
def leppard - rock of ages evil laugh at end
metallica - master of puppets evil laugh at end
dr. hook and the medicine show - cover of rolling stone
beck - ozzy
chuck berry - my ding-a-ling

other ones i thought of right away are already named

I think theres some laughter in one of the songs from Chocolate Synthesiser by Boredoms, but as with alot of things on that album it could be coming from anywhere

When the drums kick in and the song starts. It sounds like some screaming or an echoing laughter. You hear that a little more in the background throughout the song because of the, erm, singing. I'm not terribly sure if it is actually laughter or screaming so I'll listen to it again and report back.

Beach Boys - Barb(a)ra Ann

originally taken from the pastor dick pledge show on kpfa berkeley, performed by negativland and featured on their excellent series over the edge (vol 2)

lcd soundsystem- your city is a sucker!

doesn't the "Victoria" Kinks cover have some laughing in the sing-along?
And also Under the Influence of the Jesus and Mary Chain and Ticket to Ride maybe too have a chuckle...can't remember.
Inhuman has the ah ha ah ha ah ha at the beginning.

The opening track of Post Reformation TLC; "...they made such a fooss about givin' it t'me/ and I (ha)/ I spend more time getting it turned down".

There's probably more, but these spring readily to mind.

You beat me to it.