Its gripping and the acting first class. Highlights the corruption at the top of police and local government and any empathy goes to those living without hope and emeshed into the spiral of drug taking and selling as the only way of life known. What happened to Frank's son at the end of season 2? Hope some loose ends are covered in next 2 seasons.
I couldn't put it better. It also emphasises how plodding the system is. In other shows and films, wiretaps and other law-enforcement actions seem to just happen instantaneously. The Wire depicts the administrative struggle involved at each step.
Some of the best characters I've ever seen on TV are from that one show - McNulty, Bubbles, Omar, Mouzone. Bubbles especially - in any other setting he'd be the shambling druggie making an occasional appearance. The Wire shows he's a real person, a human being trying to deal with his circumstances as best he can, just as we all do. His story continues throughout and for me is one of the lynchpins of the whole show.
Re Frank's son, you mean Ziggy? Spoiler alert for anyone intending to watch it - as I recall we last see him heading off to start his prison sentence for killing 'Double G'.
There are elements of continuity through the remaining seasons but don't expect every loose end to be tied up. I think this is a show that's forthright about life not always being that neat and tidy!