Dawn of the Tiberium Age (DTA) is a stand-alone mod that combines Tiberian Dawn (C&C 95) and Red Alert. While classic mode gets as close to the original game-play and balance as possible, Enhanced mode provides improved game balance and a lot of fun new stuff. DTA features many customization options for Skirmish and multiplayer (where you can play as GDI, Nod, Allies and Soviet on over 200 maps), challenging original singleplayer missions, as well as co-op missions. Since this is a stand-alone mod, you don't require anything but the mod itself to be able to play: the original game is not required.
The Soviet Theme skirmish lobby in DTA 1.15. You might notice that the starting location selector drop-down is gone; instead the map preview's starting location indicators can be clicked on to open a menu where you can select the player that starts on the specific location.
You might also notice a star in the map list; with DTA 1.15 I've implemented Valherran's suggestion from here: Moddb.com