The Wire is quite easily the best drama ever. Best comedy between Seinfeld and The Simpsons. Seinfeld was more consistent (it didn't have 10 seasons of mediocrity), so it probably gets the nod.
Current? Breaking Bad. Also watching Lost, Justified, Modern Family, Community, Parks and Recreation. All good shows. Lost is an all-time great, but it's first season and middle years were its strongest. Breaking Bad is well on its way to being an all-time great. More people should be watching it. The others are in their first or second season, too soon to tell.
Honorable Mention to The Shield. Damn good show that ends as strong as it ever was.