I guess the Nvidia 1080TI. I purchased it 4 years ago for $699 and it's worth more now than it was then. I'd prefer a RX 6800-XT now since I'm using Linux but certainly am not going to pay today's prices for a modest upgrade. I'd have to purchase an RX6900-XT go get any noticeable speed increases and don't want to spend $1600+ for this. So maybe wait for RDNA3 or go with the new Intel Arc Alchemist cards when they get released next year.