Question
What's the best UK credit card for using abroad to avoid adding 2% exchange currency fee etc etc...
Answer
FCL, you're quite lazy, aren't you ? ;) this has been discussed frequently, and a quick search would have revealed that Nationwide is the one for which you're looking.
EDIT: have just noticed that this is not in the BA forum, as I first thought :o (checking on 'new posts') so the above is possibly a little harsh on FCL. But on reflection, probably fair :p