Brit Hop & Amyl House (1996) - This is the very first DJ mix CD I ever heard, and totally blew my mind. Has a permanent place on my iPod.
The Tunnel Mixes (1996) - Discovered this and acid in the same summer. An absolutely life-changing experience

I still get goosebumps today when the track 'Dreams' kicks in.
Perfecto Fluoro (1997) - Oakenfold before he went shit. Mixes between '97 style psy-trance and movie soundtracks. Have still never heard anything like it.