There are soooo many good filters available today, and because the sound they make is very dependent upon one’s playing style it’s really hard to make a recommendation - what works for me might not for you.
That said, I second Edwin’s shout out for the 3Leaf Groove Regulator. I also really like the 3Leaf Wonderlove (that’s what’s on my big board) and the latest version of the Proton (v4) is great, too. The Proton sounds great and more repeatable than the others, but it’s also less versatile. The Chromoton is my least favorite - it’s too fiddly and sort of sterile sounding to my ears. The SolidGoldFX Supafilter is another one I like… similar in tone to the Proton, both of which are descendants of the Mutron Branch of the filter tree.
I really love the SA Spectrum, too. There are hundreds of user presets available at the SA website, and you can audition them online without a bass or the pedal. The presets are tweakable to some degree once they are loaded on the pedal, and are infinitely tweable using the desktop or phone apps. The Spectrum can also run presets that mimic an OC-2 and flanger, which is why it’s in my small board. It sounds really good… I’m not sure that in a live mix I can tell the difference between it and a good analog filter. It solves problems. Don’t sleep on it.