I definitely need to add some, any ideas on some good ones? I've been thinking maybe polaris for a filter and I'm unsure about modulation, there's just so many modules its hard to pick out specific ones
-- amulet
I'll start with the filters first because that one is probably the easiest. Polaris great filter option in my opinion. Humpback is one I'd recommend (https://www.modulargrid.net/e/god-s-box-humpback-filter). The dopfer wasp (https://www.modulargrid.net/e/doepfer-a-124-se) is another I'd suggest as a good one to have in your rack in general. If you wanted a more "Moog" sounding LP filter I'd suggest the FWE Transistor Ladder Filter (https://www.modulargrid.net/e/fully-wired-electronics-transistor-ladder-filter), I've got a heavy personal bias towards it so you'll have to forgive me there but I'm just suggesting what I use. Its got that traditional rich moog sound whilst also being designed to sound like its got a 303 squelch when the resonance is cranked. Again excuse the personal bias, but its very affordable like most of the FWE modules. That said they are the filters I would go for personally.
Modulation I'd say Maths (https://www.modulargrid.net/e/make-noise-maths--), Batumi (https://www.modulargrid.net/e/xaoc-devices-batumi), OCHD (https://www.modulargrid.net/e/divkid-ochd) to name a couple. Not necessarily modulation as such, but one sequencer I absolutely love is the Stochastic Inspiration Generator/ SIG+ (https://www.modulargrid.net/e/stochastic-instruments-sig-4-track-stochastic-inspiration-generator). Pairing that with the Mini-Logic (https://www.modulargrid.net/e/fully-wired-electronics-mini-logic) or Multi-Logic (https://www.modulargrid.net/e/fully-wired-electronics-multi-logic), or any boolean logic based module for that matter, then patching one of the outputs into an envelope generator can be fantastic for generative or ambient patches. I totally understand what you mean about picking one out, it can be very overwhelming as there's so many of them.
Interms of utility I think it really depends on where you want to take your system and what control you want over it. If you want attenuators or something along those lines I'd suggest the Motion Mtr (https://www.modulargrid.net/e/befaco-motion-mtr) or the DPA (https://www.modulargrid.net/e/fully-wired-electronics-dual-passive-attenuator). Personal bias again (really sorry but I really am suggesting what I use daily and what I know), the DPS can be great for routing signals around your rack (https://www.modulargrid.net/e/fully-wired-electronics-dual-passive-switch). I really like using mute modules myself, especailly for generative and ambient patches, which I'd would personally use the MQM (https://www.modulargrid.net/e/fully-wired-electronics-mini-quad-mute), but the DivKid Mutes (https://www.modulargrid.net/e/divkid-mutes) would be a great alternative.
I'm not sure how you might intergrate it but Pams is a great module as well in my opinion (https://www.modulargrid.net/e/alm-busy-circuits-pamela-s-new-workout-). Disting (https://www.modulargrid.net/e/expert-sleepers-disting-mk4) might be a powerful module to have.
Hopefully that helps somehow, I had a list of suggestions ealier but they've sadly all escaped my head at the moment.