Unfortunately there's no comprehensive list on the Boards right now, but here are some of the more basic roles that could potentially appear.
Alignment Cop: Checks a player's alignment at night. Usually innocent.
Role Cop: Checks a player's role at night. Can be either alignment.
Doctor: Prevents a player from getting killed at night. Usually innocent.
Roleblocker: Prevents a selected player from using their night actions. Can be either alignment.
Tracker: Checks who a player visited with their night actions. Usually innocent.
Bulletproof: Immune to the first kill attempt on them at night. Usually innocent.
Public Speaker: Their votes are doubled, but it doesn't appear on the public tally. Usually innocent.
Vigilante: Able to kill a player at night, usually limited to one or two successful kills per game. Usually innocent.
Godfather: Appears innocent when scanned by the Alignment Cop. Always mafia.
Depending on if you want to do role madness or not you might also need some vanilla innocents and mafia with no additional powers.
I'd suggest looking at some of the mafia games hosted this past year to get a better idea of what shows up (stay away from Waluigi Time Cereal Mafia though lol, I wouldn't recommend Lightning Mafia+ either since its roles are a lot more fitted to unique mechanics in that game). You can also try looking at MafiaScum or Mafia Universe, those are some pretty good resources.
I see. There used to be a list that had all the roles used in Mafia games in the past on this forum, but for whatever reason, it was removed, hence why I'm asking for a list here. But I'll see what I can do with the roles and sources you've provided here. Thanks.
Yeah, it was removed fairly recently during some cleanup of the board since it was very outdated and had a lot of overly complex roles, a lot of them being one-off roles that were reliant on gimmicks for specific games. Maybe in the future there will be an updated role list compiled.