Another vote for the 17/3.5 SP. Rented one of the early built-in filter versions back in 1991 for a trip up to the Skagit Valley Tulip Festival.
If we're talking camera manufacturer lenses, then the Series E 70-210/4 (and the AF Nikkor version) are quite good. The E version sometimes can be had for almost nothing, unlike the AF version, which tends to be somewhat expensive in comparison. Other Nikon lenses I've been pleasantly surprised by: the 28/3.5 Nikkor-H, 135/3.5 Nikkor-Q, 200/4 Nikkor-Q, the 20/3.5 Nikkor-UD, the 50/1.4 Nikkor-S (which, as long as you don't use f/1.4, shoots very well - did a test shot recently at Kenmore Camera on an off-topic Nikon full-frame camera with my copy - tack sharp at f/5.6), and, of course, the 50/2 Nikkor-H. Pentax-wise, I was very happy with my old 55/1.8 Super-Multi-Coated Tak. Not as much with the earlier Super-Tak, but, that was still a decent lens, hung off my beater H3v that I had as a kid.
-J