Good weight for what? You need to to take into account goals, frame size, etc.....
In general, for a natural BB, I'd consider 175-200 pounds a good lean contest weight depending on frame size. Add 15-30 pounds in the off season.
For the strength sports, I'd consider the 100kg or 220-230lbs, a good class for a 5'10, decently lean man.
Just some thoughts base on observation, but there really aren't any really hard and fast rules for these things. Go by strength levels and the mirror. If you're strong and look good, be happy.