I'd much prefer a sequel, but a reboot to L.A. Noire would be just as welcome. Not only would the graphics be top-notch considering what we've seen lately with the Mafia remake set around the same time period, but I feel like Rockstar would be able to learn from some of the more glaring mistakes and improve heavily.
Notably, the whole interrogation mechanic has some glaring flaws with what the interrogation options are called, and in how it chooses to tell you whether you got an answer right.