Good Topic this.
I think a lot of my favourite choices are definatly in America. Universal have the pick of the bunch
Duelling Dragons - this is one of my all time favourite queue lines, absolutly stunning amount of detail inside the castle, with bits of themeing just about everywhere even in parts where you wouldnt think there is themeing, Its also the one ride where I dont really mind walking round the entire queue line just for another ride instead of cutting through a fire exit/baby pass line to get back in line quicker
Spiderman - Going through all the offices is pretty cool, some good attenstion to detail here
Ripsaw Falls - Some good themeing inside, and very well done
The Mummy - again quite impressive, love some of the interactive stuff you can do inside
MIB - Love the whole look of the queue, and where you pass MIB Headquarters, it looks so cool
ET - Not the greatest ride, but I love the queue line,so rich in detail, and you can easily be fooled you really are in a real forest,love all the extra stuff that goes on including ET coming up talking to you.
Pirates of the Carabean - The One in Paris has probably the best themed queue line, really looks cool some of the themeing you pass.