Matt Ryan, but he'll be franchised at the very least. Nick Foles. Teddy Bridgewater. Tyrod Taylor. Maybe Jameis Winston, rumblings about him not being the guy long term in Tampa. That's about it.
Foles maybe, but none of the rest, especially Ryan who I just don't trust and will cost way too much. Mind you, the clowns running our team do make stupid deals that cripple us (ie. Suh...)
While not a free agent one guy I would be sounding out would be Derek Carr. Up until he got hurt he looked to be up in the Elite class with the best quick release I have seen since Marino, and at the moment Gruden is blowing up the whole franchise and ruining his career in the process.
The Raiders seem to be willing to trade out anyone for a high draft pick, if we do pull the pin on Tannehill at the end of this year it may be worth considering. Either that or really bottom out next year and then hit a Quarterback heavy draft (although Gase may not have the currency to survive to that point).