2nd best Nikon full frame lens next to the Nikon 24-70 f/2.8?

2nd best Nikon full frame lens next to the Nikon 24-70 f/2.8? - 1

Possibly the 70-200mm f/2.8G ED VR II. One of the best selling, anyway…

"Best" is subjective. There's no correct answer.

What's best is really dependent on the situation. However, 14-24 f/2.8 and the 70-200 f/2.8.
The 24-70 would be not be the best lens for birders.

That's the second best, probably. The best I think is the Nikon 50mm f/1.2 (and I don't care if it's manual).

You can still find good Nikon AF 24-85 mm f/2.8~f/4.0 lenses for under $400

Check KEH.com. B&H Photo and Adorama used gear or mpb.com

If you do not mind a third party lens, like Sigma or Tamron, then you can look for 24-70 mm f/2.8 lenses made by them and which fit Nikon cameras

A non-Nikon brand lens of same specifications, such as Tamron or Sigma.

First decide if the focal lengths (24mm to 70mm) and max aperture offered (f2.8) suit your style of photography. Lenses of that spec offer medium wide-angle to modest tele. An excellent lens for weddings and other social functions, and similar "general purpose" requirements.

What results do you want from your camera/lens "system"?

Any Nikkor 50mm lens