Here in America, these guys are practically unknown, and it's a real
shame. They are one of my favorite British Invasion bands.  I bought a
good best of from amazon.co.uk on the Spectrum label #551 823-2  about a
year ago, and listen the heck out of it. Allmusic shows it as from
Polygram International with a catalogue number of 551823. From what I
can tell, all of their singles are excellent, at least until you get to
the point where Dave Dee tried to be a solo troubador.

As with the best British Invasion bands, they show a very interesting
growth curve -- they didn't seem to stick with any one groove for long,
and did them all very well.  There's some excellent drum work on most of
the early tracks, and the later tracks are some of the better highly
produced "production" singles that I've heard from the era. 

Best of all, they always seemed to have a good sense of humor. And a
high dash of sexuality. One of my friends remembers them as being
considered a "dirty" band at the time, mainly due to the overt sexuality
of "Bend It," which is a very early single.  Zabadak! Is the type of
song that most bands threw on the b-side as a joke, but DD, D, B, M & T
do it proud, sound effects, nonsense syllables, and all.

According to the credits on the Best of, their singles seem to be almost
exclusively written by the team of Howard/Blaikley, but I can't say that
I'm familiar with them as a song-writing team other than through DD, D,
B, M & T.