This is tough since I've really tooled my bag down to 8 already. I think I would keep.
Envy
Alias
XXX
Stalker
Volt
I'm torn on the Alias. It's just about my favorite disc to throw, but my Envy can cover most of the same shots, and my Tangent will give me a more consistent negative turn when I need it that the Alias can't quite do. But if we're talking forever, I just can't see giving up my favorite disc.
While these threads are not usually fun to scroll through and read all the answers with 5 discs that I don't throw, especially with no flavor text as to why, I do appreciate the thought they give me on how my current bag is built and the look back on how things can change over 3.5 years in this case.
Of the discs listed above, the only ones I still bag are the Envy and Alias, and really usually only the Envy due to the same reason I gave then, it does pretty much the same thing as the Alias.
Soon after that post, the Theory was released, which is now my only mid usually. And I tried the Crave out, which ended up being both a better Volt, and better Stalker for me.
I eventually replaced my lost XXX with a Resistor, which I in turn replaced with the Clash, realizing I really don't need the extra stability.
So, 5 discs for the rest of my life, previous post was a bit off, but shortly after my bag evolved to be very close to what it is today, and I imagine I could roll with just
Crave
Clash
Theory
Envy
Wedge
Add in a Relay and that's my go to bag right now.
3 more years from now? Maybe Axiom releases something like a Wedge and 1.6mm variants of the Crave and Clash and I'll be looking at just the Envy not changing again. We'll see.