QuoteRadeon RX 7600
Some reviewers, like Dave2D, criticize Steam Machine's only 8 GB VRAM, so the challenge should be to build a desktop PC [for a similar price] with an at least 12 GB VRAM GPU, not another 8 GB VRAM one.. And even if such a self-build is 50-100 bucks more expensive, it's worth it.
Because 8 GB VRAM is becoming more and more of an issue: youtube.com/watch?v=ric7yb1VaoA ("Gaming Laptops are in Trouble - VRAM Testing w/ @Hardwareunboxed")
Don't forget the steam cube can never upgrade its cpu/gpu and a real PC can.