For Image Quality but ----- to me IQ means more than line-pairs per milimeter; it's a total package of high sharpness and pleasing contrast with smooth bokeh. Soooo, that said here are my 3:
My short: Nikkor 28mm f1.4. However since this is an older design with a hand-ground aspheric element, you need to search out a good copy. Plan to pay for it and go through two or three before finding a beloved one. Possibly my most used lens.
My normal: Nikkor 50/1.2 D. It's a manual focus lens but delivers amazing results. I do not personally care for the way the new 58/1.4G renders, nor do the any of the current Nikkor 50 AF lenses suit me any better. The OUTUS might, but it's also MF, bigger and more expensive AND focally longer (and perhaps too long) than the 50/1.2 I already own and love. BUT, the 50/1.2 may get dropped in favor of the Sigma Art 50 when I finally get one in the upcoming weeks -- depends on how it draws, but if anything like the 35 Art then it promises to be very viable.
My long: Nikkor 85/1.4G by a whisker over the 105DC. Simply outstanding optically and nothing bad to be said anywhere about it except its weight. One other option here would be the Hassy Zeiss F 110/2 -- an amazing optic with phenomenal imaging characteristics, but it's all manual and stop-down metering. Though honestly, the 105DC is almost as sweet, is AF and electronically coupled and has the option of the DF ring. So for me, it's a really tough call between the 105DC and 85/1.4G for my longer lens -- some days it's the 105 in my bag, others the 85.
My caveats *IF* I preferred some other focal ranges: In superwide the Zeiss 18 ZF2 is tough to beat -- I prefer it over any current 21 by a fairly large margin, though Guy's F-mount converted 19mm Leica R was very sweet. (In fact I wish I had bought it when he sold it, but could not get myself to pull the trigger simply because I don't shoot that wide very often and I have a 17-35 zoom that covers that range well enough for me.) Ironically, there are NO 24's I am enamored enough with over the same 17-35 zoom to put them on this list -- but to clarify the zoom is not an iconic lens, just a worker bee that works for my needs in that wider range and why it's not on the list. In 35 it would be the Sigma Art, done. 135 would be the Zeiss, hands down one of the best optical performers I've ever seen regardless of focal length, format or manufacturer. Only reason I don't own one is because I never cozied up to the 135 as a focal length I easily visualize in. Finally in longer, the 200/2 Nikkor is amazing too, essentially right up there optically with the aforementioned ZF 135 -- my only nit being a relatively long minimum focus distance and weight...
