The operatic sounding vocal in Ben Grimm - MDK (Smokers Inc) is from this track, which is on a compilation of early electronic music: http://www.discogs.com/Walter-Carlos-Ilhan-Mimaroglu-Andres-Lewin-Richter-Tzvi-Avni-Musica-Elettronica/release/5838108
The sound at 3.07 is used in Tom & Jerry - Yamming Snacks Like Shaggy http://www.youtube.com/watch?v=z2ZbIoalBnU&noredirect=1 http://www.youtube.com/watch?v=27hoXMvVAKk
The chords used in Audiomaze - Forbidden Agenda (0.47) http://www.youtube.com/watch?v=Adr80eIIPV4 Definitely the same chords but I wonder if they're from a sample CD or something because they're much higher pitched in Forbidden Agenda yet much slower. They might have used some extra tricks to time-stretch them.
A bit of that intro vocal is used in Boyz Dem From Booby Track - Jungle Lick (Booby Trap) Comes in around 1.33 on the clip https://www.youtube.com/watch?v=UnmwlGzxjfQ
http://www.youtube.com/watch?v=q6-EEn3dBiA The synth from right at the start is used in Droppin Science Vol 1. It comes in at 2.25 and is pitched down quite a lot but it's definitely the same one. http://www.youtube.com/watch?v=2qQRRknpjSY
It looks like the Techno Grooves tune (and possibly the Frequency one) samples Frankie "O" Generator - Dance To the Rhythm (Dynamo Mix) on DFC
DJs Unite is definitely the second hand sample though as it has all the extra sounds in there
0.44 "It will never be the same" 1.27 "In all this time" http://www.youtube.com/watch?v=PsADGnUJQuk used in DJ Hazard - Never The Same http://www.youtube.com/watch?v=k-Jl6GpzwV0