I'd like to see a 'Year One' style series about Superman's early career - with a blend of Golden Age aesthetics and modern elements.
It would be set ostensibly in the 'present-day' - albeit a somewhat anachronistic present day. Much like Batman TAS evoked the 40's, this show's version of Metropolis would evoke the 30's while still being set in the present-day and featuring present-day technology, and even some retro-futuristic technology. Earth 2 on the CW Flash show would actually be a good reference point for what I'm talking about. Also, I think 'Raygun Gothic' is the term I'm really looking for.
Superman's design would be like a cross between the New 52 version (specifically from Morrison's Action) and the Fleischer cartoons. The suit will be straight from the Fleischer cartoons (yes, even the black on the symbol rather than yellow) but Superman will have the younger appearance from the New 52 (while still looking fairly rugged).
Now in terms of characters and setting - we'd have Clark at the Daily Planet, so all the usual suspects are present. Lois Lane, Jimmy Olsen, Perry White et all. This is a younger Lois before her Pulitzer or any other major accolades - she's really hungry for a story and her initial interest in Superman is purely professional, though she gradually starts to become fascinated with him in a more romantic sense. I'd even keep the angle of Clark and Lois being rivals, with Lois initially being mean to Clark but gradually warming up to him as they realize they have a lot in common as journalists.
Now onto Superman. He's in his early twenties. He has all his powers but he's not all-powerful. A powerful enough explosion can hurt him, if only a little. Bullets may bounce off him but certain powerful energy weapons could really knock the wind out of him. He has to exert himself to life a huge oil tanker. He can fly, but he can't fly into space yet (at this point, he's never left the planet). In terms of personality, he's pretty tough and at the same time cool and collected. He can have a bit of a playful attitude to his job, but he's tough on criminals and villains. Above all, he's a man of action - always ready to charge into a situation. Sometimes he's a bit too headstrong and over-aggressive, confident that his powers can get the job done. He learns that its sometimes necessary to stay calm and assess the situation first. This is part of his gradual character development. He also initially is kinda like a vigilante of sorts. He avoids the media (other than interviews to Lois) and speaks to the authorities only if necessary (and again, with a vibe that he's in charge, rather than any deference - though gradually mutual trust and respect builds between Superman and the authorities). As Clark Kent, he's 'mild mannered' but still a pretty dedicated and tough reporter. His mild attitude belies his fiery spirit as a journalist - something which Lois finds misleading and annoys her when 'Smallville' keeps scooping her.
For villains I'd have Lex Luthor obviously. He's a scientist and corporate mogul who believes he 'owns' Metropolis and is resentful of their growing enchantment with Superman. Intergang would be a major presence in Metropolis as well. In addition, the likes of Parasite, Live Wire, Toyman, Metallo, Atomic Skull, Bizarro, Ultra-Humanite etc. will gradually make their appearances. Luthor mostly works in the background, orchestrating many schemes through his minions and subordinates while himself managing to stay clean. He initially tries to use his influence to turn the authorities against Superman and declare him a vigilante but is frustrated by the growing public support for him.
In terms of backstory - when the series begins, Superman has been around in Metropolis for around six months, but Clark Kent is just beginning his job at the Daily Planet (there can be a reference to him having briefly worked at the Daily Star ala the Morrison version). There will be the occasional flashback and exposition to fill out his backstory, but not a lot will be revealed initially. He gradually developed his powers through his teens. When he was around 15, he was shown the rocketship and saw Jor-El and Lara's message. He knows he's the sole survivor of Krypton but knows nothing beyond that of his heritage - other than the S symbol. The suit is made from Kryptonian materials from the ship and is indestructible. Johnathan Kent dies when Clark is around 18 and before he dies he asks Clark to use his powers to help mankind, which is Clark's immediate motivation to become Superman. Martha is still alive and well, and there might be the odd episode where Clark returns to Smallville and meets her, as well as Lana Lang and Peter Ross, but not often.
Finally, the finale of the second season would deal with Brainiac invading Earth, and a loose adaptation of Morrison's opening Action arc, mixed with Geoff John's 'Brainiac' story. Superman saves earth from Brainiac's invasion, is firmly renowned now as a global hero, and learns a lot more about his Kryptonian heritage. He gains access to Kryptonian tech that he uses to build the Fortress of Solitude in the Arctic. Finally, he gets a new suit or modifies the old one, making it brighter, and getting the yellow in the chest symbol rather than black.
After this point, from Season 3 onwards. The show would have a more Silver Age aesthetic (Metropolis is rebuilt after the invasion), and more stories inspired by the Silver Age and the modern era. There would definitely be more sci-fi and space-faring adventures and villains. The Lois and Clark relationship would gradually start to develop. Also, other superheroes start appearing and teaming up with Superman. Other developments could include Supergirl coming to earth, Luthor becoming a full-blown supervillain, etc.