the original Ibanez AD-80 is the bee's knees afaic. Warmest, most natural sounding decay, with infinite regeneration capability. Reissues are really excellent too, but just not...quite... as killer. 18volt pedal, be careful about supplying the correct voltage!
Moog Moogerfooger Analog Delay (around $600)
T-Rex Replica (around $400; gotta love that T-Rex Roommate tube reverb pedal as well! Next best thing to springs imo)
Way Huge Aquapuss
the vintage MXR, a la Jerry(late 70's/early 80's)
the ADA Multi-Effects Delay a la Jerry (early 80's/90's) digital
the vintage Ibanez AD-9, a la Bob (late 70's/early 80's)
...the Robert Keeley-modded Ibanez AD-9 (he very recently stopped production, so grab them where you can) very killer, with an exp pedal option.
Robert Keeley-modded Boss DD-3 with fx loop -digital
...Echoplex!! and Fulltone's version of the ultimate Echoplex, the Fulltone Tube Tape Echo or TTE... this thing is truly SICK. It's a fairly large unit, not a pedal, and More of a studio tool. At $1100 or so, if you take one to a gig (or even practice!) you are crazy, imho, but... DAMNnnnnnn. Juicy as anything you've ever heard.
and of course... the ubiquitous Line 6 DL-4. I personally am not too crazy about 'em but I'm friends w/ lots of players who go nuts over L6 stuff.
"There, in huge black letters, was 'The Grateful Dead'. It just... cancelled my mind out."-Garcia