Most of my "lust list" doesn't quite exist: Canon 200/1.8 EF to fit my Nikon D1h orPentax A* 200/2.8 to fit my Nikon D1h.
Olympus 21/2.0 to fit my Nikon D1h, or that Pentax 20/1.4 that they prototyped but didn't produce. 85/1.4 Nikkor with SWM internal motor. Pentax LX that takes Nikon MD-4 motor drive and has normal strap lugs. Full-frame DSLR that takes pentax screw mount lenses (which does exist, in the form of the EOS1Ds with an adapter) K105/2.8, K150/4, K18/3.5, K15/3.5, all of which might as well not have existed based on how hard they are to find, and expensive. SMC-T 500/4.5, SMC-T 15/3.5 (ditto) Pentax K200/2.5 (which exists, and I could theoretically afford, but I can't justify). And there's the quest for a 20mm pentax K-mount lens, which has been pre-empted by the needs of my Ford Escort. DJE