Sid Meier's Civilization IV

Sweet Half-Life: Relit is an unofficial remaster of the Sweet Half-Life mod that makes it compatible with new versions of the game and includes reworked maps, weapons, monsters, effects, and much more.

Tiberium Resurrection is a total conversion for Tiberian Sun that adds a new campaign about the struggle for control over the Mutants, accompanied by original cutscenes, pixel art, and voice acting. The mod includes new units, reworked balance, improved versions of old maps, and completely new locations for campaign, skirmish, and multiplayer.

Portal: Epic Edition is a hardcore mod for Portal that completely reimagines the campaign. Levels are pushed to the limit of difficulty: turrets everywhere, enemies from Half-Life, and new mechanics. There is also a separate Epic version with extreme challenges, bugs as part of the gameplay, and a reworked final battle.

USS Darkstar is a cult mod for Half-Life where you find yourself aboard a "Zoological Research Vessel" studying alien creatures. It all starts as a routine scientific mission, but eventually escalates into a tense adventure in the confined space of a spaceship full of unexpected threats.

Tiberium Crisis 2: Dawn Fall is a mod for Yuri's Revenge that combines the ideas of C&C3 and C&C4 on the classic engine and has achieved impressive progress in graphics quality. The mod adds a new campaign that presents an alternative reimagining of the events of Tiberian Twilight and significantly deviates from canon.