Kind of a tough choice... what I need it to do is the primary factor when I'm picking put a delay, but these are the few that I keep coming back to, in no particular order...
1. TC 2290 - Digital perfection, great modulation, very flexible... and all the cool routing things it will do, too.
2. Electro-Harmonix Deluxe Memory Man - just delay time available to do some really cool short/medium delays. The modulation is simply angelic. Such a beautiful sound!
3. Eventide Eclipse (H3000DSE, GTR4000) - Yeah, I know it's not just a delay, but what it can do with delays... band delays, reverse shifters... and so much more. Any of the three (Eclipse, H3000, 4000), even the Space pedal. Not just a delay, but a soundscape limited only by the imagination.
4. Maestro Echoplex EP-3 - Nothing sounds like tape, and the ability to make it wow and flutter and all the other tape goodness. Just hard to leave this off the list.
I have others, some I really like, some too specific to use for more than one sound, but the four above... those are the ones I will not do without.
OK, honorable mention does to the old Boss DM-3. That was my first delay (bought it new). I've had so much fun with it over the years, and it's still fun to play around with. Not particularly versatile, not always the best sounding, but it's just fun enough to inspire as much as any of my earlier picks.
edited for spelling
