Stacking overdrives can be awesome.

I started back when I was rack rigging, using various combinations of RBI, RPM, VT-RM (two of the three). Note: I wound up using a
parallel wiring configuration that I thought was more effective than series, but series still worked great.
When I switched to pedals, I've stacked the various Tech 21 devices I've owned with success (and I've owned a bunch).
There are some caveats to stacking. If you're thrilled with the sound of a dirt pedal soloed, there may be no benefit to adding another. The pedals should be complimentary: e.g. two sizzly dirt pedals may sound harsh; it's usually better to combine a sizzly one with a neutral or warm one. Also, it sometimes helps to adjust settings from their norm: maybe dial back the distortion level on each.
Caveats aside: when I get the settings right, I can combine three* distortion pedals to sound great in any combination: soloed, A+B, A+C, B+C, and even the "nuclear option", A+B+C.
And yes, isolated power! Either a Voodoo Labs ISO-5, or CIOKS DC-5.
*I'm sure some can stack more with success, but my max happens to be three