I love electric locomotives. Some guys like steam, others diesel. I have always been fascinated by electrics however. LGB electric locos ( eloks ) have a selector switch that allows for quick and easy conversion to allow the loco to take power through the pantograph. I'd like to see O scale manufacturers do the same.
Most recent MTH electrics have that feature.
You can also easily convert an atlas model most of the time.
As mentioned above, MTH has switches for the pantograph on their electrics. Here is an example on my Crocodile engine. I have removed the hatch cover so you can se the access port. Hopefully the crocodile won't eat the hatch cover.