Long story I used to have one of the original Subdecay Echoboxes, actually before that I had an EHX Memory Man. When the pedal (and all of its neighbors) were stolen out of my car, I replaced it with the newer version. What they had done was class up the box, make it more subtle, less pushy, more like the MXR Carbon Copy. It creates echos that tend to want to space themselves behind your clean signal, the gain structure is pretty polite, kind of an extended echo working like a reverb pedal (to my shoegazey ears) in that it adds dimension without taking over. You have to really jack the dials to get it to oscillate, or make any kind of mess. It's a handy pedal, but I sometimes need broader, more psychedelic strokes.

Short story who knows of a delay pedal that tends to make big clouds of echo, and can slip into analogy (don't really care if it's actual or digital) smear, oscillation, and semi-controllable noise when coaxed. I need a dangerous delay.

dod fx 96. my favorite analog delay ever. they stretched one BBD chip to unheard of lengths, when you max out the delay (and pot inside for more time) it gets wacky and wierd. also has a "tape effect" which is just a LPF which is cool cause it kinda modulates and gives funky tones to the repeats. cheap as hell, super underrated, i probably just ruined them by mentioning them here, now radiohead or some bullshit will be using them and they'll be at klon centaur prices. damnit.

I used to have that Boss/Roland Space Echo pedal, the RE-20 I believe. Lots o' fun. Read up on the "twist" function.

Sold that years ago though; now I very much enjoy the Minifooger delay. Expression pedal input and a dip switch inside to make it control either rate or feedback. Plus they threw in a distortion circuit just for kicks!

I recently picked up the Deluxe Memory Boy. It has expression, tap tempo, a pretty strong delay mix (blend), and the ability to choose dotted 8th notes, etc. ("tap divide"). It can oscillate like Superballs inna blender.

Point of fact, I bought the regular Memory Boy because my need was for something simpler, and the MB does chorus and vibrato.

Delay Llama Plus. I somehow got an early prototype on ebay for very cheap - I wouldn't have spent anywhere near the going rate on it at the time, but now if my pedalboard was stolen it'd be the very first thing I'd replace. Sound-wise it's a perfect mix of the old DM2/obscure Japanese smear-y, blurry analog delay and the kind of dirtier, starker original DMM. And personally, unless I'm doing something that stacks delays on top of reverbs on top of delays, I only use analog delays - I find they don't clutter the signal in the same way that digital delays do. It's the only thing I've ever been an analog purist about. I've played plenty of digital delays that are great analog sims tonally, but they always feel clutter-y when I play them. Because of its lack of clutter (to me), the hold button on the Delay Llama+ doesn't behave the way a hold on a digital delay ever could - you can get a swirling crazy mess going and still play *with* it and not *against* it if you want to. If that makes sense.

"I don't need time, I need a deadline." -Duke Ellington

"I liked the holes in it as much as I liked what was in them." -Tom Waits

Try the Danelectro Wasabi Forward-Reverse delay if you can. I haven't pushed it into oscillation, so I don't know about that side of it, but the tone is fantastic. I used to have a Boss DM2 and that was great, but the Wasabi actually improves the tone of the guitar. It's also the best reverse delay out there, and allows you to have the mix 100% wet, which is kind of the whole point of reverse delay, IMO. The cheap Dano delays, like FAB echo, can be modded to do all kinds of crazy self-oscillation. I think essentially the same mods can be applied to just about any delay. I think most of them use the same main chip (PTsomethingorother) anyway.
The Behringer Vintage Delay is a DM2 clone; it's cheap and sounds a lot like the original. A change of a pot value or two could get you what you're after, possibly.

get a hammered sound from guitar or bass! http://www.stringhammer.com
hand-made version to raise money for manufacturing... kind of like kickstarter, but you get a fully functional item now

Whoa, that box is crazy, and that commercial is hilarious. I don't know that I'd ever use anything that complicated, but it's cool to see. Just when I think we've reached peak stompbox market I find more, and more unique boxes.

Been through the gamut of delays, too many to mention. Still own a lot of them, but mostly I get bored and move on. (I keep a SD Vapor Trail for analog cuz I haven't found better.) Just (finally) got a Boss RE-20 and it is the most fun I've had with a delay in decades - it seems to be the one that is most like playing an instrument. Just the right amount of controls plus a certain amount of pixie dust.