Ok here's what I think is the correct time line you should watch:
1)Macross Zero (horrible prequel IMO, tho Roy showing up was awesome)
*2a)Super Dimensional Fortress Macross (Loved the show, but could deal without all the drama. Still a damn good show though)
*2b)Super Dimensional Macross : Do You Remember Love? (the movie pretty much sums up the original Macross except it looks infinitely better than the TV series)
3)Macross 7 (has a few returning characters from the original Macross, go Jenius family)
4)Macross Frontier (Direct sequel to Macross 7, looks to be pretty promising)
5)Macross Plus (awesome OVA series, should've been a TV series though I'm still content with it)
Extra : Robotech isn't Macross except for the first season. It was renamed because Harmony Gold (I think) put together three different shows (Southern Cross and Genesis Climber Mospeada, which both happen to be completely unrelated to Macross) under one storyline so that all three shows hold a continuing time line. In Southern Cross, they completely changed to the ending from what was just both races getting along with each other to the signaling of the Inbit (their supposed sworn enemy) coming by the release of protoculture energy. Genesis Climber Mospeada didn't do bad as a stand alone show, it had some pretty good pop culture references (Like the show at Carnegie Hall) and a decent story by itself. On a side note, Yoshitaka Amano was the character designer for the show (Who also did Gatchaman, Casshern (TV), and Tekkaman).
EDIT: I decided to add Macross(TV) on what order to watch the show because goty has a point. The original Macross is still part of the story (DYRL is an alternate telling of the story, but it's still pretty amazing IMO) so it deserves to be watched.