Bad Medicine is in E minor, no? The G is way too prominent for A major, although I guess the whole rock & roll scale thing allows for it. It feels more minorish than Teenagers (ironic, given the titles).

Also, for the record, I never cared all that much for Teenagers. Famous Last Words (as I said), the title track (super close behind), The Sharpest Lives, This is How I Disappear, House of Wolves - these are all super duper great, though.