Very tough call for me.
I've just started exploring Devin, I love his production, really enjoy both Ki and Ghost, but apart from that, I've only been able to listen to Ziltoid more than once. Explored SYL once, some time ago, not for me (apart from the production) and his solo albums are mostly too hard for me too. I listened to Terria and that's supposed to be his softest.
Oh and I really, really like Devlab, but didn't enjoy The Hummer.
Steven Wilson, yeah, well, where can I start...
I know I'm pretty much alone on this, but I can't really enjoy PT's latest albums anymore. I used to love In Absentia, but it's not for me anymore. I really do like Sky Moves Sideways, and (really?) Voyage 34, Signify and Metanoia. But in my opnion PT is some of the weakest works SW has done.
Bass Communion - I can't get enough of all of their material, I love the Continuum albums, Ghosts on Magnetic Tape, I, II and Loss.
No-Man - much underpraised band. From their breakbeat-laden early works, up until Schoolyard Ghost, nearly all of their albums are wonderful.
IEM - I like the way they let their songs evolve in a jammy kinda way. Own only one album, but they don't seem to have much more.
Solo work - I've just started to 'understand' his solo work, but I just can't seem to really get past his voice (I'm sorry Jackie).
Oh, and Blackfield is really not for me either. I totally lost interest in them after listening to the first album a couple of times.
Vote goes to SW.