You honestly can't go wrong with any of Bowie's 70s output. Some of his early folky stuff is lame, and Diamond Dogs is pretty much the most diappointing album ever, but the rest of it is just about great.
Eno's stuff ranges from stuff similar to the poppy Berlin album songs to the more ambient stuff. Here Come the Warm Jets is one of his poppy experimental albums. Another Green world is a sort of combo poppy/ambient album. John Cale, Robert Fripp, and Phil Collins guest on bits and pieces of it.
I don't think my Bowie MD has left my minidisc player for more than a few hours in a long, long time.
EDIT: Fear of Music and More Songs About Buildings and Food are the other two Eno Heads albums, though Remain in Light is by far the one he had the most input on (writing credits on all but 2 songs). After being booted from the band by the other asshole members, Eno went on to record My Life in the Bush of Ghosts, which is pretty awesome. Between certain songs with Bowie, his Heads output, and his solo work with Byrne, you could see the enormous influence Eno had on the emergence of world music.
Another Green World is like listening to someone elses dream. The few songs with lyrics are free associative, bizarre, but strangely maudlin or nostalgic. The album goes between sparse but surrounding beautiful soundscape and somewhat uncomforting and even frighting bits. I have no idea how he came up with this record. It's amazing, no doubt. And after listening to Eno (and Bowie's Heroes and Scary Monsters) you really come to appreciate the guitar work of Robert Fripp.