The following series are marking anniversaries this year:
50 years: The Jetsons.
45 years: Birdman & the Galaxy Trio, Samson & Goliath, Journey to the Center of the Earth, Shazzan, The Herculoids, Moby Dick & the Mighty Mightor, George of the Jungle, Superman/Aquaman Hour of Adventure, Super President.
40 years: Amazing Chan & the Chan Clan, The New Scooby-Doo Movies, Josie & the Pussycats in Outer Space, Sealab 2020, The Barkleys, The Houndcats, The Roman Holidays, The ABC Saturday Superstar Movie, Fat Albert & the Cosby Kids, The Brady Kids.
35 years: C. B. Bears, The Skatebirds, The All-New Super Friends Hour, Scooby's All-Star Laff-a-Lympics, Space Sentinels.
30 years: Shirt Tales, Gilligan's Planet, Meatballs & Spaghetti, Pandamonium, G. I. Joe: A Real American Hero, Mork & Mindy (animated series), The Incredible Hulk (2nd animated series).
25 years: Bravestarr.
20 years: Batman: The Animated Series, Wild West C.O.W.Boys of Moo Mesa.
10 years: Stargate: Infinity, US debuts of Ultimate Muscle, Kirby: Right Back at Ya, Fighting Foodons.
If there's a favorite of yours that I've missed, please let me know and remind me.