If you had to pick just a handful of capacitors..

[SkrillBill]

I've pretty much come to the conclusion that i need to have 0.1uF decoupling caps on hand at all times, a few other values then stock the rest as needed.

Yep.  You'll always find a circuit somewhere that someone has used a calculation to determine the EXACT capacitor value and specifies something really weird and rare.  Usually you can replace it with a more common value with little to no effect.

I've been at this for only a few months, but the capacitors I have actually used would be:

22pF  Ceramic
100nF Ceramic or poly - almost every circuit to decouple signal stuff
1uF Elec - almost every circuit to smooth/decouple power rails.
100uF Elec
1000uF Elec - power supply circuits to smooth/decouple the output.

I think there was a 47pF once.  The rest have stayed in their bags more or less.

I do need to pay more attention to my voltage ratings on the elecs though, some are 30V, some 16V.  I don't think I've built a circuit that requires more than 15V though.

If possible I'll get 60v. Not because i need it for any of my projects, but because i wouldn't have to buy duplicate values. I mean, there's not a functional difference in performance *other* than the amount of voltage in 15v vs 60v caps right?

I could mostly live with the following - very rarely use anything else

100n and 100u through-hole
100n, 1u and 10u ceramic SMD

This, minus SMD. Not quite to SMD yet, although i have removed lot of SMD stuff with a hotair gun...