My saddest would be my entire Free Radical collection & the constant reminder that TimeSplitters is now owned by Crytek, who would rather make boring yet visually nice games (Crysis 1 was alright though). Also Valkyria Chronicles due that damn cutscene sniper. Project Diva.
Im fine with the situation when germany takes over britain in a strategy game. After all, they have to go somewhere after I enforce mass exodus from their lands.