Just saying "most reliable" doesn't really give anyone enough
criteria to judge. I think a lot of people love Eggbeaters and
Times because they're easy to "mash into," which is important
for city riding. Neither release unexpectedly, and the cleats are
relatively cheap and should fit in a standard mountain bike
shoe that will let you walk around easier.

SPD pedals are not unreliable in any way, and I would guess
that anyone who has had serious SPD failure did so because
their pedals were not set up properly. If anything, I would
argue that SPDs offer great protection than ATACs and
Eggbeaters, and increased efficiency, but they're not always
the most practical choice for city riding.