Throughout this week and next, Gamasutra is presenting a year-end retrospective, discussing notable games, events, developers, and industry figures of 2007. The end of the year tends to be a time of reflection, and it’s been said that this is one of gaming’s most prolific – if not its best – years yet. 2007 has seen all kinds of evolutions on the experience of gaming, and while we perhaps haven’t hit yet on that elusive formula for true emotional engagement, this year’s offering feels a lot like nudging up against the boundary of everything we’ve previously believed games are capable of being, in terms of the ways they can affect, immerse and even permanently change us. As the industry struggled to find that magic balance between story and gameplay, compelling characters took front and center. The reasons we play span from getting the opportunity to be a hero – or a villain – to experiencing a new perspective, a different ability, a new angle on the world, a new sense of a self that is not us. It can be argued that the key to a game experience is a lucky cocktail of features that make us love – or loathe – our characters, that our final impression will hinge on what that character was, or was not able to do. With that in mind, we take a look this week at five of the year’s most aberrant, interesting, compelling and effective characters in games. Minor spoilers. 5. Frédéric Chopin (Tri-Crescendo's Eternal Sonata, Xbox 360) Aside from some pretty colors and lovely music, as an RPG, Eternal Sonata was ordinary in most ways – and that’s the remarkable thing. That one of the most derivative genres in console gaming could so seamlessly integrate the life, history and musical work of a real-life composer in such a facile, cavalier way stands out as one of those examples of the kind of engagement that games can make possible. After all, Frédéric Chopin is not a fictional character, and the interpretation of his life as a dream in a fantasy game encouraged more than a few RPG fans to learn about him, maybe play a piano tune or two. And a character becomes much more thought-provoking given the concept that everything you are playing and seeing might just be a dream in the head of a man as he dies. 4. Kratos (Sony Santa Monica's God of War II, PS2) The first God of War made a compelling anti-hero of the haunted soldier, and God of War II brings us Kratos as a God. With character conventions that could serve as a primer on Greek tragedy, the piquant conflict between Kratos’ condition of power and his inner torment and powerlessness gives greater relevance to the almost artful, ravenous violence that characterizes the gameplay, with each brutal stroke conveying the desperation of bitterness and a quest for redemption and absolution that remains ever out of Kratos’ reach. 3. Andrew Ryan (2K Boston's BioShock, PC/Xbox 360) The architect of BioShock’s Rapture serves as a cautionary example of the danger of pure philosophy. Though he’s introduced as an antagonist, Ryan quickly becomes as sympathetic as he is so bitterly wrong – despite his hard-line objectivist-influenced ideals that delineate artists from parasites, men from slaves, his greatest crime save for fatal arrogance was perhaps believing in humankind too much. When the ensuing conflict forced him to compromise, over time, his ideals, that uncompromising faith in his beliefs were worth sacrificing his life to attempt to convey to his son. BioShock’s one weakness was that, as that son, the player couldn’t elect to adopt that philosophy to thwart his own abuse. 2. GLaDOS (Valve's Portal, PC/console) The sleeper hit of the year, Portal, couldn’t have brought phrases like “I’m doing science” into common parlance without GLaDOS, the decaying mainframe computer with a personality disorder. The relationship between GLaDOS and the protagonist has been called everything from passive-aggressive to maternal to an out-and-out feminist manifesto. An antagonist who joyfully lies and then admits it, and then contradicts it again, who praises and then excoriates, threatens and begs, who sings you a song when you defeat her -- Portal is undoubtedly an excellent game, but GLaDOS is what really makes it happen. 1. You (You, Everywhere) This year’s trends showed us clearly that networked gaming is here to stay. Social virtual worlds inspired by game concepts did a tentative introductory dance around gaming itself, and social networking, communication and personalization quickly distinguished themselves as lynchpin features that suddenly no game can do without. Blizzard’s unshakable World of Warcraft nation seems invincible, Mass Effect allowed players to customize the protagonist to an unprecedented degree -- from every response he or she has, right down to the width of the eyes. Much was also made this year of choice in games as an absolute necessity – the player wants to personalize the experience, see themselves reflected in it. After chafing for years under conventions that forced film-like linear stories on players perhaps too hard, gamers have quickly declared that they’re quite happy to make their own stories, to place their preferences and their own character concepts front-and-center in an open world. The audience has set a new bar for the year to come, as gamers begin demanding game experiences where their own will is the star. [Do you agree or disagree with these picks? Feel free to sign on and comment below. We'll pick the best Gamasutra reader comments on each list for our final retrospective, to debut late next week. Already-posted lists include Top 5 Downloadable Games.]