If you're just stocking up for future experiments, why the diversity? Just pick some general purpose NPN and PNP (3904/3906, BC547/557 etc.) and maybe some darlingtons.
If you're fixing something, chances are you don't have that exact part anyway, so either you stock up on every part out there (not feasible), or order what is needed for the task. That, of course, if you can't just put a general purpose part in there as a replacement.
Having a ton of equivalent parts can be confusing - e.g. not knowing what the part is beforehand.
Also, NPNs are much more used than PNPs, so you might want to buy 50 NPNs and 20 PNPs.