Gillingham in Kent - Jillingham
Gillingham in Dorset - Guillingham

Whenever I've been to Wiveliscombe it was pronounced Wivel-ISScombe (or just Wivvey), none of that Wivelscum business, which reminds me of the American dipplemat (diplomat).

And then there is Congresbury in North Somerset, pronounced Congsbury, not the mealy-mouthed Coomsbury you get from elderly aunts.