Depends on what you're looking for. In general analog is great if you want short delay or echo/slapback with few repeats. Analog is more natural sounding to me and the repeats will loose clarity for each regeneration. Digital if you want long delay and clean repeats, plus pingpong, stereo, etc. The issue with digital is although the repeats is clear, it sounds ... digital
For analog, it's hard to beat the Carbon Copy. I haven't found any decent digital pedal so I use rack, like TC Electronic D-two, M-one, or an older Lexicon, can't remember the model now, basically stuffs that we use for our PA.