Are you having amnesia or sth? You even posted after I proposed the topic and elaborated on it on the last discussion thread. And nobody but you brought "genre" into this. The OP talks about topics, not genres
Lies can be spun in an infinite amount of creative ways. One could look at the liar, the ones being lied to, the effects, the struggle to maintain a lie. Of course, this stretches from simple "I'm lying to my friends" to big con artistry, cheating in casionos to big government coverups.
Lies exist in all walks of life, small and big ones, good and bad. They exist in every genre, and could thus, as a theme, give the writers a massive amount of freedom.
What I AM enthusiastic about is the idea of Lies. Why? Because you can write lies into everything. We lie on a regular basis in real life, and fantasy heroes, as well as superheroes, lie about their identities or deeds all the time. Bruce Wayne is hiding his role as the Dark Knight from the world and won't hesitate lying about it, or setting up situations that'd disprove suspicions of others that it might be him.
The Government lies about its "war on terror", or about how they aren't getting basically blackmailed by the industry titans. The media makes a whole business out of lying, as do actors who assume roles for an audience.
People lie to save others, people lie to get an out-of-jail card in the future, people lie to get what they want, people lie to steal others blind. They can also lie to avoid hurting somebody, which can also backfire.
Lies have a LOT of room for interpretation, moral ambiguity, interesting settings and characters. A story could be about an unrepentent arsehole lying to further his own greed, or it could be about a joking trickster who deceives his audience for whichever reasons. It could be about a guy or girl lying to their family or lover about something, or an employee lying about his work. It could be about a scientist lying about his research, for good or ill. It could be about a priest deceiving himself in his beliefs, or a parent telling his daughter that Santa is real.
There's a shitload of room for interesting stories, both very human ones close to the heart to spectacular games and complex drama. The funny thing with lies is that they can be both a means to an end or a catalyst setting a whole line of events into motion. They can solve problems and create new ones.
That's good stuff for written stories, especially since those allow for closer examination of the involved characters' motivations and thought processes. Something that movies really suck at.