There are many good mentions here. I'm comparing my planned vacation roster versus the locations listed.
I live near LA and I make it a point to avoid the Nakatomi Building. The number of dead bodies that fall out of that thing is simply appalling.
If your dimensional transporter is working, you may want to avoid Earth Alpha. Pollution levels approach lethal, and the governing corporations have a tendency to use death as a tool of discharging service.
As an aside, Ankh-Morpork
is no place for the faint of heart. Unless you plan to donate said heart to a sausage maker named Dibbler...
Oh, and I've done the research. Despite beautiful beaches and rolling green hills, the country of Genosha is anything BUT tourist friendly. Particularly if you exhibit "unusual" abilities.