'Now & Again'
and maybe 'Kyle XY'. (I'm still five episodes back on that show. Saving them for a rainy day... a rainier day.)
That is, in the face of cancellation, they finished on a cliff-hanger in the hopes the network would have to bring them back to see it resolved.* But in each of those cases, it was not to be; and 'T:TSCC' may be joining their club.
On the other hand, there's the American version of 'Life On Mars', which was given the chance to resolve its mysteries before cancellation. And was the audience in general thankful?
Just sayin', is all.....
*Actually, in the case of 'Coronet Blue', by the time the network decided to bring back the summer hit, everyone involved had already signed contracts for new projects.