My favorite Vangelis albums are the Blade Runner soundtrack and El Greco.
And Pete Namlook ... He's done so much great music, it's hard to point out one album (I couldn't even do that with vangelis, haha). Anyways, check out the two albums he and Geir Jenssen (Biosphere) has done, The Fires of Orc (1 and 2). Solarized is also a damn fine album, and also his Moog series done with Klaus Schulze are very good, check the "best of"; The Evolution of the Dark Side of the Moog.
Also, the album from Pete Namlook I've listened to the most is perhaps the 4voice album from 1992, but that's not only ambient, most of the tracks are 4x4 trance tracks, a few ambient tracks and even a couple of hardcore tracks.
I didn't keep this short and helpful, sorry.