I know, a slightly strange request. But I couldn't think of a better comparison than the game series, as to the type of series I'm looking for. Basically, any recommendations for a sci-fi (or perhaps Mass Effect is more space opera?) series that involves exploration, some action -- whether it be ground-based or space battles -- and includes following a heroic figure or figures as they try and defend humanity against an impending evil. Ironically, the actual novels in the ME universe aren't what I'm looking for, as they don't really contain the same interesting things the game has.