So far I'm pretty happy with where I've got to with the modules I've bought, my next purchase thoughts are around the following:
Expert Sleepers Disting Mk4
Noise Engineering Clep Diaz
2hp Arp
2hp RND
Happy Nerding FX Aid
Also need a Clock Multiplier
Or
Monsoon (NI Clouds Clone)
I need a bit more Random going into the Turing Machine, I feel I need a slow clock as the main clock with Multiplier for the lighter jingly/twinkly bits, a Clouds Clone and/or more effects for some textural washes of sound to go around what I already have (and derived from what I already have).
Enjoy your spare HP, don't rush to fill every last space, this is not like filling sticker books. Resist the urge to 'complete' your rack, its never complete so just relax.