It is difficult to say who I like the most since every one of them has his/her character, motives, values etc. they are all very well done. It is pretty much the warlords but maybe even with deeper characters, since there are bonds within them, and way better than Nardo's Akatsuki.
Probably Chrollo, his thoughtful and complex personality (we have seen sadness for Ubovgin, rage for Shalnark and Kortopi, playful and challenging with Zeno) are fascinating. After him there is probably Hiei Feitan or even Nobunaga, Shizaku is good too and even Kalluto, it is already difficult to pull a 2nd :p
Yet imo they will not die, at the very least not all of them. Chrollo vs Hisoka was already a dead match but that felt strange from the very strange since Togashi could not burn Hisoka nor Chrollo, he spended too much time to make their characters which are loved by all the fandom and are symbols of HxH almost as Gon and Killua. So imo some spiders will die, probably even on the ship if the s*** hits the fan (they find Hisoka and so Kurapika and we have an awesome love triangle Kurapika -> Chrollo -> Hisoka not to count the other spiders and even Illumi lol plus the zodiacs and princes who have to keep the peace on the ship, that will probably be the last thing which happens on the ship, after that it could even sink lol), but of course not Chrollo nor Hisoka and not even Illumi (even if imo he is more expandable than Chrollo and Hisoka), they risked their lives not long ago (manga time at least) and like I said vefoire are HxH symbols. They could die but at the very end of the manga, that would be the only acceptable places for the likes of Chrollo and Hisoka to die. Then, I expect, or I would like to see, some spider action on the dark continent. That would be the first time we see the spider actually cornered to take something seriously, maybe even some group work (excluding what Chrollo did with Shalnark and Kortopi).