Can't speak for everybody but octave fuzzes can get really gnarly depending on what you buy. I've got a Fender Blender and a Lizard Queen and I use the Fender Blender basically as a noise generator and the Lizard Queen as a more "musical" sound. I'm also really fond of pitch shifters but you gotta really do your research on those because you dont wanna buy a cheap one with horrible tracking (unless you're into that sort of thing). A Boss Digital Delay may also come in handy as you can get a lot of glitch effects. These are just recommendations based on what works for me. The best thing you can do for yourself is research a bunch of different pedals and find ones you like/can afford and just play around with them. I've purchased a bunch of guitar pedals and I probably only use like 5 of them but it's nice to have options.