The only ones of the systems listed here that I've rode completely -- that is, every bit of line open to the public -- are Atlanta (unless there's been a new extension lately that I've not noticed) and Glasgow (both loops, inner and outer). I haven't been all the way out to the end of the Pittsburgh/Bay Point line of BART, you see, or I could count that as well.
Edit, 14 Aug 12:00: And here are the logos of some fixed-guideway transit systems that don't show up on the "Metros" site but which I have ridden:
Sponsors Two of our reliable sponsors of past shows don't have dealer tables at L.A.con IV, which leaves me short of sponsors for prizes. I can fill out the prize pool with stuff from Emerald City -- we have a lot of books piled up here -- to go with the two Cargo Cult certificates and one Casa de Fruta/Hollister in 2008 package -- but I need eight sets of prizes even though we probably won't give them all away. Any suggestions? Anyone there have contacts to dealers you think might be willing to stump up a gift certificate? I'm reluctant to cold-call people at this point, if only because I'm short of time.