OK so having been through the whole thread I've been inspired to post just a couple more.
First up I've always loved this blissed out version of Royksopp's Remind Me, which I first heard on a Jacques Lu Cont FabricLIVE mix CD back in the days I was spending every weekend at London's greatest superclub.
On the CD he rather cleverly mixed it into the classical piece Also Sprach Zarathustra, as will forever be associated with 2001: A Space Odyssey. And to this day I can't listen to the song without hearing that moving classical intro coming in at the end, even though obviously it doesn't anywhere other than on that mix cd.
And because somebody already mentioned EBTG and Todd Terry I'm also dropping this turn of the century filter house classic which has such a wonderful warm glow and catchy hook that I never want it to end. Chuck in Tracey Thorn's simple breathy vocals and this is house music at its finest. Perhaps it's more of a bootleg than a remix, being a mashup of EBTG's Wrong and Sandy Rivera's Come Into My Room, however it was the Lazydog Bootleg MIX that got this over all the radio stations at the time, so I think it should be allowed. Gosh it's nice