I first waded into the Leijiverse last year with the short anime Ozuma (which I disliked very much) and the film Arcadia of My Youth. This year, especially with Yamato 2199, I encouraged myself to delve into these vast and daunting sub-universes even further.
Of all of the big franchises and meta-series, I think the Leijiverse was the most intimidating. It took me a while to learn what characters were linked to others and which series were completely separate from others. (Captain Harlock, Queen Emeraldas, Galaxy Express 999 and Maetel Legend are all connected. Yamato is its own thing.) Naturally I didn't watch everything in the optimal order, but the pieces were certainly not difficult to put together.
In addition, I watched much more older anime this year: the original Lupin III TV series, I completed Rose of Versailles, and Aim for the Ace! just to name a few. I have absolutely no problem watching anime from the 70s and 80s, though the animation definitely can be a distraction. (This particularly rang true for Aim for the Ace!) But there are plenty more older series that I'd like to check out at some point.