Jiggilypuff, Blissey,Delcatty, Kricitune but there other moves to put Pokemon to sleep E.G. Dark Void
Sing is not a TM (Technical Machine). It is a move that only certain Pokemon learn. You can only learn it by leveling up certain Pokemon (Skitty, for example, learns Sing by leveling up).
Chatot learns sing at level 13.
there are lots the top ones would be sleep powder and sing or lulaby only a few Pokemon know them like butterfree or bulbasaur but only jet Jackson learns lulaby
Slakoth
She learns how to sing.
he learns it at level 66
none of the fifth generation Pokemon learn it but in black and white sneasel learns it at level 42 houndoom learns it at level 26 and houndour learns it at level 25.
camerupt, groudon.
Likitung
Evee
The only Pokemon who learns it is Rhyperior (lv 61). You get him by trading a Rhydon to a friend with the hold item Protector attached.
a chatot can learn sing