Sites I do not recommend
I'll explain which sites I advise avoiding and why. The linked reports let you check the details yourself. Some reports are old: this is not a new analysis of every file these sites host today.
IGG Games and associated sites
IGG-GAMES, PCGAMES TORRENTS, CRACKED-GAMES and LOADGAMES. The linked reports describe in-game advertising, added DRM, miners/adware, hostile redirects and removal of release credits.
The Pirate Bay / KickassTorrents
Listed because of the risk of malicious uploads. A torrent being indexed or popular is not evidence that its uploader or files are trustworthy.
Cracking Patching / STEAMHUB / Ocean of Games / Get Into PC
These names appear in the cited reports for malware risks or inclusion in CS.RIN's unsafe-source list. Domains recorded there: crackingpatching.com, steamhub.co, oceanofgames.com and getintopc.com.
SteamUnlocked / GOGUnlocked
steamunlocked.net, steamunlocked.pro and gogunlocked.com: the original list cites malicious redirects, files from IGG and missing release credits.
RePack-Games
repack-games.com: unwanted software during installation and republished releases without author credits are the reasons given in the cited reports.
Sites using CPY / SKIDROW names
cpyskidrow.com, cpygames.com, cpygamestorrent.com and skidrowcpy.games. Be careful with sites presenting themselves as scene groups and advertising cracks that do not exist. A group's name in a domain does not make it an official site.
Fake FitGirl, ElAmigos and R.G. Mechanics sites
Domains identified in the cited reports: fitgirl-repacks.website, fitgirlrepacks.co, elamigos-games.com, repack-mechanics.com and rgmechanics.com. Do not confuse these with the repackers' own pages.
Skidrow & Reloaded
skidrowreloaded.com: criticised in the cited discussions for using known scene names and insufficient attribution of P2P authors, sometimes replaced by the generic label P2P.
Other sites on the list
nosTEAM (nosteam.ro): malware reports. GETGAMEZ (getgamez.net), ALL GAMES FOR YOU (agfy.co) and AliTorrents (alltorrents.co): listed as unsafe; AGFY is also described as a scam in the original.
FreeTP (freetp.org), Game3rb (game3rb.com) and MrPcGamer (mrpcgamer.co): missing author credits and inclusion in the unsafe-source list are the stated reasons.