Scene groups (such as CODEX, CPY, SKIDROW, etc) do not have public websites. If you find a site using the name of a scene group, they are impersonators. Beware of these sites as they tend to package their releases with malware.
For PC games piracy news (crack releases, DRM news etc), visit /r/CrackWatch
Sites labeled repacks are for releases that have been repacked from the original scene release. Their intent is to provide pre-cracked installations as well as smaller filesizes, and in many cases, also provide DLCs included in the installation.
rutor.info - Game repack site
rarbg.to - Yes, they offer game torrents too.
[Repacks] fitgirl-repacks.site - Popular website for highly compressed game repacks -- games can take several hours to install. Only recommended if you have very slow or data-capped internet.
[Repacks] repack.info
[Repacks] otxataba.net / aka Xatab
[Repacks] kaoskrew.org
[Repacks] rg-mechanics.org - Mirrors RG Mechanics' repacks. Their home location is the tapochek.net forums
ovagames.com - Offers Scene game downloads
scnlog.me - Scene game releases
forum.torrminatorr.com - Scene and p2p game releases
gog-games.com - Untouched GOG games. No cracks needed.
Steam Underground - cs.rin.ru - Dedicated game piracy forum. Best parts are the discussion and the different types of tools especially the multiplayer ones. Game links aren't always provided (especially for scene releases; they recommend some external sites in their FAQ) but when they are, they are on free file hosting services like zippyshare so that's another plus. Also includes early access games.
gamecopyworld.com - Game trainers, cheats, and standalone cracks for games
myabandonware.com - Old/retro/"abandoned" games
[Mobile] forum.mobilism.org - Mobile cracked games
[iOS] iphonecake.com - iOS cracked games (and apps)
[Mac] nxmac.com - Mac games
[Mac] web.archive.org/.../macgames-download.com - Web archive of the now-defunct macgames-download
[Private] forums.snahp.it - One of the best private DDL forums. Used to be public. Links are provided on free hosters
[Repacks] kaoskrew.org
[Repacks] kapitalsin.com
[Repacks] fitgirl-repacks.site - DDL links are only valid for new releases since they get die off quickly. Popular website for highly compressed game repacks -- games can take several hours to install. Only recommended if you have very slow or data-capped internet.
/r/Roms - Roms
the-eye.eu - large collection of multi-platform console roms
emuparadise.me - Incredibly large ROM library. Use this script to reinstate the download links.
emulation.gametechwiki.com - large wiki with several links to ROM/ISO dumps.
Vimm's Lair - large collection of ROMs
CDRomance - formally NicoBlog
Gazellegames.net (GGn) - Best source for games for enthusiasts. Carries games from basically any console. Can be joined through RED
PixelCove - Another pretty great source of games for the enthusiast crowd.
TorrentLeech - One of the largest general private trackers
alpharatio.cc - A general private tracker focused on scene releases. Inferior in content compared to other general trackers like IPT, TL, FL etc but has a very strong request section. Great for requests for which personalised trackers don't exist or aren't good enough. Can be joined through MAM and RED during AR's global invites period, keep an eye out
Filelist - One of the largest general private trackers. Romanian tracker, but media content will typically include dual language audio (English and Romanian).
IPTorrents - The largest general private tracker