What games/movie should I play/watch from the Final Fantasy 7 series?

So I like Final Fantasy 7 and I want to replay the actual series of Final Fantasy 7 (NOT the FF series as a whole). I only have the original FF7 and Dirge of Cerberus but I want will watch Advent Children on youtube. I wanna do everything in chronological order so i was gonna play FF7, then watch AC, then play DoC but then I heard about the other games. I know it's for the phone but do you think I should get them? I don't want to unless there really good. BTW, where can I watch the full version of AC for free on the internet