Just a note: don't use wiki for anime series(well, as a first source anyway), use TV Tropes, which will give you more information, hide spoilers, and frequently point you to related shows.
Legend of Galactic Heroes (Anime) - TV Tropes
Personally, I would wait for the new series before even considering watching the old. That will help you decide whether the old series might be worth the time. There are enough newer, better looking, higher production value shows out there that won't take nearly so long to get through. I suggest maybe Aldnoah:Zero or Valrave The Liberator. Aldnoah:Zero features politics, a princess, death, destruction, really good looking mecha, Mars vs Earth, and one of the best cliffhangers in anime at the end of the first season. Not much of the way of videos from the show on youtube, but here is the season 1 opener, which gives a decent feel for the show:
Valrave the Liberator is far, far in the future, people living on Dyson spheres, war, mecha, and lots of action. Again, not much for videos on youtube, but here is a trailer: