Percy Pigs from M&S are the king of chewy streets.
They contain real pork fat.
( FoldsFive, Wed 27 May 2009, 15:51, archived)

more of this sort of thing.
Tesco Mint Imperials also contain pork gelatine, and are therefore king of the mint imperials. Despite the hysterical ranting of some people on internet product review sites.
( Moon Girl Technologies horrendous beanbag, Wed 27 May 2009, 15:52, archived)

ASDA marshmallows with strawberry centers
contain both pork AND beef.

I think they win.
(thediscokingpin, Wed 27 May 2009, 16:06, archived)

oh my goodness me,
I shall have to try some just on principle now.
( Moon Girl Technologies horrendous beanbag, Wed 27 May 2009, 16:06, archived)