I'll vote for anything CTA. Some 4000's would be fantastic, or maybe some 2000's. Heck, even a re-issue of the 6000's would be fine by me ... I just need more CTA! Or, crazy thought, some North Shore or CA&E (granted, 3rd rail did North Shore but kind of spendy for the 3 car set ... too much $$$ for me).
I need something/anything ... actually can run a train now: http://ctalayout.blogspot.com/
CTA Fan