Always both
…in the category…wooow, what a long and winding magic sonic tail…a delay can always sound fulfilling…what do i need a reverb for…or the other way around…
but in proper mixing, when it’s not only about this one or two elements u wanna drown in nice xtra spatial behaviour, but need to work on dedicated placement in stereofield and frequencyrange, u can’t even start to ask THIS silly question…room/space and repetative reflections are BOTH PRETTY ESSENTIAL…
Also keen to hear if that’s replaced the need for both from owners. See also the Eventide Ultratap - it really appeals for the rhythmic possibilities but the fact you can smear the repeats towards more of a reverb caught my attention.
I think like a few folk have touched on, delay is mainly a fun, creative, maybe rhythmic concern for me, while reverb is creative but lapses into mixing too. In conclusion, gimme all of it!
Go-to reverbs: Meris Mercury7, Live 11’s Hybrid Reverb and Valhalla’s Supermassive. I also use the Microcosm’s reverb though do find myself wishing I could rearrange the order to filter into ‘verb. Raised this as a feature request actually, though maybe not possible (also requested a smooth filter and switchable filter types).
Go-to delays: I’ve been kidding myself on that I’m lacking a creative stereo delay since selling an Earthquaker Devices Avalanche Run (do miss it) and should really just let my Eventide PitchFactor do some simple stuff. Love the DOD Rubberneck. Beyond that totally made-up and happy enough with Live’s Echo, Gated Delay, the new spectral devices. Spoiled to be honest!
I thought that somebody might have pointed this out by now but my hasty scan through the thread says otherwise…
So here it is: reverb is made out of delays. 
I’ll show myself out.
I have nothing against reverb itself, but it seems like much of the time it is overused and abused, giving it a bad name. I would recommend to anyone planning to add reverb to a track or instrument to put it off as long as possible until the work is already brilliant without it.
I don’t follow that advice with delay, as it is on every guitar part I write. 100% of the time. Reverb just feels like a heavier smear and potentially more offensive.
A good reverb seems more difficult to create than a good delay. When synths have FX built into them, the reverb is typically not the best. I prefer a good reverb because they’re more difficult to come by. You can create your own delay FX with sequencing and volume/filter/etc. changes.
I’ve often felt a good reverb is a way to hide your track and be lazy, instead of making a pad for your track just let a big reverb be a pad. While a good delay is a awesome creative tool and can lead you to writing unexpected music. So delay any day.
I like reverb, with lots of predelay. I’ve been thinking about building a plate reverb at some point. Also experimenting with distortion units on a mixer fx-loop before the reverb for extra texture and filth is something I’m very interested in.
I love delay too but in most cases I’m more interested in creating spaces that are part of the sound.
I love reverb, and Sinevibe did a really great job on Typhon.
I’m fond of inverted reverbs.
In the other hand I really enjoy abusing delays, especially tweaking feedback, filters and time to get crazy loops and reveal the delay limits (and true nature).
Can’t choose, sorry.
I used throw delay on everything possible and obsess over different delays quite a bit, using not much reverb or none at all. During the past months, I started to use more reverb and less, almost no delay at all.
Funny how that basically reversed^^
I like reverb for the boring traditional application (pretend to sound like some sort of room, hall or cavern) and for more creative stuff. OTOH, I don’t like how it can make a mix sound like mud when used improperly, especially for playing live, so I’m always watching out for that.
Delay can be inspirational, although when I’m coming up with an instrumental part to add to someone else’s song, it’s hit-or-miss because sometimes the songwriter likes what the delay adds, and sometimes they feel it messes up the rhythmic concept they had in mind for the song.
What exactly is making this cacophony of beautiful dirt?
So that’s a load of modular stuff. Sound basically achieved by running a saw and triangle through a ring mod in parallel, then through a bunch of tubes for satiration, then a waveshaper, then through two reverbs, a four band eq and two band enhancer, then some more distortion (FET), then through a quadraverb.
Sold it all now though, but you can do pretty much all of that with a pro 2 and a decent reverb or two.
If I could only take one to a desert island it would be reverb. I could make believe I’m all sorts of places 
The way I look at it is reverb is fake and echo is real. Those echoes are really happening in a sense, while digital reverb always forces you to suspend your disbelief that you are in an infinite cavern or somewhere unnatural. That’s too many steps for my little brain. I just want that straight repeat straight into my ear no wondering where it is
The reverb is just a brunch of echoes.
Massively prefer reverb, however as I learned from the Pro2, you can do a hell of a lot with a few delays together.
I do find delay quite repetitive though…
I’d keep Echoboy if I had to take only one with me, any day 
i failed to consider