Mad Men

I LOVE LOVE LOVE this show! Definitely one of my faves!

It's on AMC and the new season (season 3) starts this summer...

It's a very realistic story based in the early 60's, around the advertising firm Sterling Cooper. Check out this Wikipedia desc. on the show: http://en.wikipedia.org/wiki/Mad_Men

I actually discovered that they're running episodes from season 2 right now. You can check out the schedule at their website: http://www.amctv.com/originals/madmen/. 

I'd highly recommend renting season 1 and renting or watching season 2 so you can be ready for season 3 this summer. The show is amazing!