Reddit mentions of dbx 1215 Dual-Channel, 15-Band Graphic Equalizer

There arent any crucial pedals. Personally i dont care about tremolo or phaser pedals really and arent going to get them(also i can hook bias fx on ipad in amps fx loop and get any effects). Reverb i dont have much need for, because there is built in reverb in my amp and its pretty much what i look in for a reverb 99% of the times, it also has a sweet chorus, so no need for that either. And it gives all the distortion i need, which i can shape with rack eq, i might get some fuzz at some point, but dont really feel the need for that just now.

The point is that peoples need depend on what sound they want to get and on the current gear. But there are some pedals that people often like to have. Since you dont do any gigging, you could use rack effects, which have their upsides, and pretty much only downside is that there is no foot button to kick it on/off(some you can control with midi foot controller tho) and the size. For example, i got this for 90€ used https://www.amazon.com/DBX-1215-Dual-Graphic-Equalizer/dp/B0015IUSVW , which is pretty much the same price as some crappy eq pedals with not many channels, but this has 2 channels(can put one before amp to shape the overdriven sound and boost, and other channel in fx loop to shape the overall sound), so to do what this is capable(2xeq pedal), you would pay double for some shitty ones. I would highly suggest getting something like that, if you think eq pedal is for you. Also there are tons of reverb etc and multi fx rack effects around for cheap price, especially if you look for used. Some behringer stuff you could get for like 50-70 bucks used.

Tube screamer as someone mentioned is a nice pedal(i wouldnt say its a must have for metal tho), if you want a boost pedal that boosts mids bit more than bass or treble. But again you could do very similar boost with the rack eq i have(reason why i just sold my tube screamer).

It just all depends on what you want, there are no crucial must have pedals.