Ahh... the strange ways of British TV, confusing foreigners again!
Yes, it was short, but at an hour and a half long, it's less a series and more the equivalent of a mini-series. Very common format for our dramas; lots of stories are shown in feature length episodes over three or four consecutive nights, or weekly. In a lot of cases, they are one-offs, with no intention of another series. Lynda La Plante has had a lot of her work done like that. Widows is a TV classic and more recently a handful of stories under the banner Trial And Retribution. Book adaptations are often done like this, with a "series" of A Touch of Frost or Miss Marple actually being three or four stories made like films. If you liked the format of Sherlock, there are a lot of these you would like, but I wouldn't know where to start!
Oh, I suppose David Tenant in
Secret Smile. That was good, because he played a villain.
Anyway, I'm not remotely surprised you enjoyed Sherlock, Marie. Were you aware it was written by Stephen Moffat, who is the current writer/producer of Doctor Who and worked with Russell T. Davies very closely throughout the Eccleston/Tenant runs? He called Sherlock, "Doctor Who, an hour later" in reference to the darker tone, aimed at a late evening audience.
Actually, I believe Benedict Cumberbatch even auditioned for the current Doctor. And Matt Smith? He
auditioned for Watson!