The Hairy Bowsies (a piss-take Irish ballad group with over-the-top Republican tendancies, courtesy of the comedian Paul Woodfull) had me laughing til I cried the first time I heard them. Their album, "Publocked" has a whole host of maudlin ballads and hard-core patriotism. It's very tongue in cheek. And the songs all sound scarily genuine. My favourite is "Flow river flow", with a chorus that goes:

"Flow, river, flow
F*ck off to the sea
Go where you are wanted
To the desert of Gobi"

They also have a send-up of "The praties they grow small" entitled "The potatoes aren't looking the best". Twisted, but very, very funny. The interview with him describing the concept of "geographical folk" (singing songs about hills, rivers and mountains with the group Wild Mountain Badger) is pure genius.

There's more info about them here and here.