Red Alert 2 Yuri's revenge is an excellent expansion of the first game.
The gameplay is even better than the first game since there is a wider choise of factions available. Graphics are the same as RA2. There are 2 campaigns, the russian and the allied. Unfortunately there is not one for Yuri's side. The story takes place shortly after the original's end, and basically its concept is that Yuri made an army and turned against the other two faction with his psychic weaponery, which is really fun since most units have some unique humoristic voices and funny accents.
But the most interesting and addictive feature of the game is its multiplayer, where your real strategic abilities will show up.
I really reccomend this game, even for today's status, since its a really nice example of a game that does not need the ultra DX11 shell shading 3D Nasa graphics to be fun.