I like odd sized gear, Brit shoe box sized integrated amps & separates, triangular cassette decks like the one from Yamaha & Nakamichi or top loading ones like the early Tandberg cassette decks, The 200 series of Meridian gear, boxy CD players like Proceed PCD2. Fi X & Y and most tube amps with their tubes exposed. Also the tall cassette decks like the early Akai or computer keyboard Aiwa ADF series.
Additionally, a stack of Perreaux, Tandberg, or Revox gear is eye catching as well as is a stack of ads Atelier.