I've not yet visited Europe--I'm saving that for the Millennium, LOL. When my parents went in the '70s I requested three souvenirs: an Eiffel Tower rivet, a Notre Dame Cathedral gargoyle, and the Pietá's brass nameplate. What I got was flecks of Tower paint.
The funny thing is I was neutral before I saw it. I had seen the replica outside and debated whether to pay to see the original inside at The Academia. My guidebook said it was worth it though. Fortunately I decided to do so.