Starters =

A sporty bike would be the Suzuki GS500 is an excellent starter bike. It's not overly powerful aby any means, but it'll haul ass around town.

A cruiser type bike would be the Honda Shadow.... oh I can't remember 450 or 500 or something like that... very similar in performance to the GS if just a little slower.

There are actually plenty of other sub-liter bikes that make great starters but they're probably a bit less popular.