For 2D? My usual taste is I'd always be up for a number 6, occasionally a 7, and an 8 every now and then.
For 3D? It's hard to say because I don't think the theoretical limit has ever been naturally achieved(fake shit doesn't count)
https://x.com/towa8a
Stuff like this is some of the biggest I've seen and still feels too small but is very good