Just returned from a 5 day round trip in our MX5 taking in France, Luxembourg and Belgium. We used our trusty TomTom to steer us around which it did without fail.
However the pronunciation of some of the town names was hilarious which set me thinking as to who has heard the daftest pronunciation.
Our best was shortly after leaving the ferry at Calais and approaching ‘Arras’ on the A26 when the TT told us to turn towards "Our A*se’.
Nearly took the car off the road we were laughing so much
must be more sophisticated version of Tom Tom than mine, as mine doesn’t use any place names, just gives directions and possibly road numbers? I do however like to use the proper accent when not in England, so I have used Irish and Scottish voices in the last couple of years, and will be looking for a French accent for 2012. Sometimes even the most sober sounding voice can come up with some weird expressions though. The Scottish one (I found for free via tomtom online) is extremely sarcastic (and funny!) when you make a wrong turn, then proceeds to remind you every minute or so with a cough,!
Neither does mine. I use a Joanna Lumley-soundalike though, since she’s very firm if I miss the turn.
Friends of mine in the US use an Australian voice on their Garmin, which does do a pretty good job of strangling local place names.
Mine has John Cleese. I love it. My wife hates it though, especially when he says, “You have reached your destination, you can get out now but dont expect me to carry your bags”
try any welsh names, they jus ain’t good 
I was using Ozzy Osbourne (Not for young ears LOL). Am using Sharon at the moment. Got about 20 voices. Whose do you want?