Some of their classics:
"Jose Mourinho, Jose Mourinho, Jose Mourinho"
"Diego, Diego, Diego"
"Chelsea, Chelsea, Chelsea"
Although the worst chant in the league is "Na Na Na Na, Na Na Na Na, Heeeey, Man United". Like, what the fuck? Man United has four syllables, not two. It doesn't fit in the place of 'goodbye'. Either United fans can't count, or they're just painfully unimaginative to not come up with a better chant.