I love homebrew on classic (and not so classic) consoles. I tend to work on too many projects, which limits what I get done. My first computer was an Atari 400 with the 32KB memory expansion and the cassette drive. I eventually updated the memory with the Mosaic 64KB expansion, switched to the Percom double-density disk drive, and added the BKey full-stroke replacement keyboard. I still have it... that computer was a lot of fun, and lasted quite a while. I eventually replaced it with an Amiga 500.
My favorite Atari has to be my first - that old A400. I really loved that machine.
My favorite games would be Necromancer, Alley Cat, Pitfall II, Seven Cities of Gold, Archon I & II, The Eidolon, Rescue on Fractulus, Drol, and of course, MULE. There are many other games I enjoy playing, but those are at the top of the list.