I use the EBL rechargeable 9V whenever I can. (Dollar Store Panasonic's for the others)
EBL 9V Rechargeable Batteries Lithium ion 9V 600mAh Batteries
Mine is a 2 pack with the recharger and it was inexpensive to buy, and they've save me from tossing many 9V single use batteries into the garbage.
For those talking about the drain curve... these are rechargeable, so much of that does not matter. We don't have to wait months to recharge, you can charge the day before the big gig, or every 4 weeks. Lithiums don't have memory effect, so "topping up" before a gig is great.
Mainly, have more rechargeable batteries than instruments/pedals needing them, and rotate their use. I numbered my batteries with a marker, to help me track that.
I still use single use 9V for some instruments, because the above rechargeable is physically a little larger than a single use 9V, and they do not fit inside the battery compartment for my acoustic Takemine guitar, and 1 pedal IIRC.
When I do buy single use, I go to the dollar store and buy Panasonic. Cheap. Works as well as the others to me.