There are a few choices out there. I'm onboard with the Carrera guys. While Carrera is a top notch track it offers you the choice of running 3 scales. I can run 1/43, 1/32 and 1/24. The power needed is different but it does open your fun to lots of different cars. As stated before, I too would take the less expensive route and buy analog. If you find yourself enjoying it, then try digital. It's an absolute blast.
If possible go to hobby store and see the pieces side by side. While IMO, Carrera looks and drives nicer Scalextric does fit more in the space. If you plan to have more space in the future, Carrera may be the way to go.
Bruce