My old History teacher in school would say 'proctol', for 'protocol', and always pronounced 'Hertzegovina' as 'Herezgovnia'.

Couple of favourites from BBC newsreaders:
'Patten' (when referring to 'pattern').
'Modren' (Modern).
'Wed-nes-day' (Wednesday).
'Drawring' (drawing).

B.
(of course, The Reverend William Archibald Spooner takes the biscuit)