Well, the story sure us getting interesting and the anime (the second season) is catching up quite well too
If it is about the question "If you could pilot one of the IS in that story, which would you choose?", then I'd probably go for the customized Uchigane Sarashiki Kanzashi is using (awesome design and firepower, screw the shield power draining sword)
And Ichika?
Well, he sure has a fun life situation:
1) Crazily talented older sister who keeps comparing his abilities (IS control abilities and such) to her own, flawless abilities and always concludes that he is made of 80% stupidity, 10% good friends and 10% dumb luck/talent, but treats him as if she expected 70% talent/sill/smartness and 30% luck, good friends, etc.
2) He is the only guy who pilots an IS and it looks like girls suck at giving IS piloting advice to guys (or at least to Ichika, although Charlotte/Charl managed THE best learning speed in him). Also, if he asked ANY girl at IS academy to help him with piloting the'd pretty much screw up because 60% of their brain would be occupied by "OhmygodIhaveIchikaformyself" at all times, making the learning useless
3) He's indecisive as hell, I mean her you got some girls who like him:
-) Gotanda Ran: She likes him, but he keeps being oblivious to that
-) Shinonono Houki: "First" childhood friend
-) Cecilia Alcott: Ended up falling for him after just barely defeating him in volume one (and that was only because Ichika had no idea his only weapon would deplete his shields)
-) Lingyin Huang ("Rin"): "Second" childhood friend
-) Charlotte Dunois: Initially pretended to be u guy in order to get Ichika's IS data (her asshole daddy got her to do that- shame on him), but fell for him as well after being found out in the shower

-) Laura Bodewig: German girl with eyepatch that never spoke a word of german in the anime, fell for him after the Laura+Houki vs. Ichika+Charles (Charlottes identity as a woman was revealed to the school after the duel) lost
-) Sarashiki Kanzashi: Didn't get a personal IS because the lab had to make Ichika's IS all of a sudden, but joined the harem afterwards
-) Sarashiki Tatenashi: Kanzashi's older sister and student council president. Not sure if she is actually in love with Ichika, but she sure enjoys teasing him
And even though their affections for him are quite obvious at times, he ALWAYS manages to piss them off by apparently choosing one of them (or them thinking that he chose) and ten ending up screwing up, usually followed by them trying to scold/chase/hit/kill him (I think trying to shoot him with IS weaponry like Rin did after hearing that Charles was actually a girl and they spent some time together in the bath would count as murder attempt, even though Laura saved his bacon then)
4) He got an organisation that doesn't really like him (phantom task) and Shinonono Tabane DID send some unmanned IS to him (or his general location) and ruined his day
(Yes, they were made by Tabane. I mean the IS core is unknown technology, impossible to be produced by anyone besides Tabane and nobody has any idea how to get an IS without a woman inside into motion either (well, Ichika is a guy, but he's a special case). So even if you don't read into the latest chapters, as soon as we get to hear about the part that the Golem's cores were unregistered ones and only Tabane knows how they are made, it of course makes Tabane the #1 suspect for making the IS drones