Meh, speaking of replacements I'd love to see Trek carried off in a bold new step forward.
You know, big ship with a crew including pretty much all the races we know and love going to other galaxies. Deal with races like the Andromedans, the machine planet that made V'Ger, etc.
If you need a villain, how about the race that seeded the humanoids? Have their society collapse, and the few people who harness their technology set themselves up as mage-lords. The difference between it and the cliche' chariot of the gods thing? They actually do think it's magic and not technology. (Solves my issue with Stargate which is why do so many non-gould have access to starship systems which by their very nature show that the gould aren't gods? If they had to have ships having them mind controlled like the Ori would make sense to keep the ruse...) ...and who wouldn't think it cool to see aliens in funny robes firing mini photon torpedoes like magic missiles?
Of course the two taboos would be not having extradimensional aliens or time travel. Except for two set aside multipart episodes. Godlike aliens welcome, but the fangasm tech that the Federation explorer team has is enough to make them more comic relief. (Trelane tries to teleport the team and finds his fingers hurting and the Andorian scientist smirking)