Hot take: the Dreamcast is the best shelf you are not buying
The Dreamcast lost the war in about eighteen months, and that is exactly why it rules. A short commercial life means a tight, weird, high-quality library with almost no filler — Sega swung for the fences because they had nothing to lose.
What makes it special
Arcade-perfect fighters, the maddest sports games ever made, and a run of experimental gems that never got sequels. It booted fast, the controller had a little screen in it, and it was online before anyone was ready. For an action-game shop it is a goldmine: the shelf is all killer.
Buying one second-hand
The two things to check are the optical drive (they wear, so we test a stack of GD-ROMs on every unit) and the clock battery — a dead one just means re-setting the date on boot, not a dealbreaker. Ours ship as complete sets, tested, with the date set and a controller in the box.
Grab one before the collector market notices again. It always does.