Mrs.D is a huuuuge fan of John Thaw in his role as Inspector Morse, so she got this (season 1 + the pilot movie, "Regan") from the library (we also recently watched him in an incredible performance in "The Sign of Four").
I saw this (Sweeney) when I was a student in Edinburgh in 1976, and remembered it as much more violent and rough than it seems now -- pretty tame by today's standards. I thought it was the best (and pretty much only good) show on British tv at the time.
Dennis Waterman went on to a much later role in New Tricks, and (probably) other stuff I'm not aware of.
Watching series 2, it strikes me that Guy Ritchie may have filched some of 'his' ideas of villainy from The Sweeney. I think I like it better than series 1, it seems really polished, especially the camera work and editing. Bonus: it looks fantastic on our old CRT tv! Plots are a little uneven, but I don't mind. MrsD. considers it very violent -- I don't recall her remarking so about S1, but since she is such a slobbering fan of JT, I expect she'll continue enduring the savage punchups and rather ludicrous car chases regardless.