I've been reading since ~Jan 2016 and finally decided to create a forum account in time for the 25th anniversary!
My favorite arc off the top of my head is That Which Redeems, though I'd have to do some thinking and rereading for a definite answer. I don't know if I'll be posting that often, though I did have a theory on the Anima dimension that I might put in a spec thread at some point.
Also wondering how things will go after the current arc. Hereti-Corp was (probably) permanently wrapped up after the last chapter, we'll see if this is curtains for the cult of K'Z'K/Poopy Pants. There's still a lot of other running plot threads, but these two are some of the comic's biggest and longest-lasting bad guys. There's still the vampire war though, which is a plot thread that's been going for longer than both. It might also be significant to the current arc since we saw Sam earlier, and the "Immortal King" title is ambiguous enough that it could refer to him as well as Farahn.