Sharpest possible AFS lens for D5100, Help!

Just picked up a D5100 and love this camera but now I am finding that the high rez 16 mega pixel sensor is totally ruthless and downright unforgiving of any lens faults or unsharpness.

Coming from a D40, D40X and D5000, lenses that seemed super sharp on those cameras suddenly have weakness on the D5100. For example my favorite lens the 16-85 vr shows that it is not as sharp as I thought it was even at F/8 when used on the D5100 at anything over 70mm. On my 12 mega pixel D5000 it showed stellar sharpness across the board. Another example my 18-55 that was great on the D40 and D40x and even D5000 is unacceptable on the D5100 for sharpness.

Here is my question. What is the sharpest AFS lens or lenses Nikon makes for this great camera that is making even my 16-85 VR look quite average? This can be either a zoom or a prime. I shoot mostly landscapes so I don't need anything terriibly fast. I just need something sharp up to the capability of this new sensor. Help!