I think everyone has his guilty pleasure which you wouldn't recommend wholeheartedly to your friends. Mine's is definitely Obsidian's spy-RPG Alpha Protocoll. I personally enjoyed it very much even though it's a wobbly, inconsistent game that gets a few things right. It's filled with so many awkward and glitchy bits you get the feeling that it should've spent way more time in development. If you thought shooting in Mass Effect 1 was imprecise, Alpha Protocoll's is even worse. But I adored the game nonetheless because of its nonlinear storytelling and the possiblity of influencing the personality of the protagonist through decisions. Thank you Obisidan.
I just started playing this, and it's definitely a gem in the rough.