[clivehawkins]

I grew up with 'You're welcome' so obviously that's the most natural form for me.
I use 'my pleasure' occasionally and that's about it.
However, 'no problem' doesn't rub me up the wrong way as it seems to with some. To me it sounds an Americanism - just another way to say the same thing. Personally I like hearing mother-tongue speakers saying things in a different way, especially Australians (G'day, beauty, beaut, ripper etc). It just makes it all the more interesting, don't you think?