"Just one"
Sorry, can't limit myself like that.
Drama:
1) Breaking Bad
2) The Sopranos
3) True Detective S1 (2 sucked, not seen 3 yet but looks promising)
4) Hannibal
5) Fargo (only seen S1, really need to get back to this one)
Comedy:
1) Seinfeld
2) The Simpsons S1-10
3) Community (S1-3 are excellent. 4 was average, 5 was pretty good. Not seen 6)
4) Arrested Development (S1-2 excellent, 3 really good, 4 decent)
Anime:
1) Cowboy Bebop
2) Neon Genesis Evangelion/End of Evangelion (the two Rebuild movies are also excellent, but dreading seeing 3 based on its reception)
3) Fullmetal Alchemist 2003/FMA Brotherhood (both have their strengths to me)
4) FLCL (original, Progressive was pretty good but definitely not on par with original, not seen Alternative yet)
5) Baccano!
Cartoons is tough, I can't really rank my all-time favorites (I know Simpsons stands out among the live-action comedies, but I had to acknowledge it). I love Batman TAS, Justice League/JLU, Beast Wars, Rugrats, OG Looney Tunes, Avatar TLA/Korra, Young Justice, Adventure Time, Over the Garden Wall, Samurai Jack, Bojack Horseman, Gravity Falls, Green Eggs and Ham*, etc. I think it's more difficult since I've been watching cartoons my whole life. I've only been an anime fan for 12 years now, and all the drama/comedy shows except for Seinfeld I never saw until after high school. Since cartoons have always been there with me, it makes it more difficult to acknowledge some and not others, they all wowed me in one way or another.
*for real on this one, yes there is a modern Dr. Suess adaptation that is not only competent but downright excellent. I hope any future adaptations of his work be handled by people this creative and not the always-aim-for-genericness group that is Illumination (still can't believe after decades of refusing any more adaptations after the clusterfuck production of the 90's Mario movie that it's Illumination that Nintendo agreed to let adapt their series. Please look forward to an underwhelming and forgettable Mario movie, SO worth the wait...)