Do you clean the outsides of your gaming machine/consoles or you just let them be and hope for the best?

How about the insides, do you open the things and clean it? How often?

I clean my electronics maybe once or twice every year.

Never. By the time it becomes an issue I'm gonna buy a new one anyway.

Exteriors get cleaned along with everything else, but it's not much of maintenance because it's all aesthetics and not functionality. I don't worry too much about interiors though. Occassionally I vacuum some dust from inside of my PC, but I don't really touch anything else. Opening a PC is quite easy but can't really say the same about consoles and other devices. And yes, I know vacuuming the insides is a horrible idea. I've been lucky with it so far and I'm pretty careful with it, so I continue doing it. Eventually something's probably going to break though.

I just wipe the dust off of it from time to time.

Occasionally I'll blow on the console, and some dust will come off. Good as new.

Stick them in the dishwasher every 3 months. Dries out nicely in the microwave.

I move the console around almost daily, dust has little chance to accumulate on the vents. What happens in the inside stay in the inside. Maybe once a year I'll slide the vacuum cleaner along the intake vents.
Now I have this crazy theory that dust doesn't settle inside my amp as I keep it on 24/7. Always warmer air rising up (passive cooling), dust can't float down. Still looks clean inside after many years. Unlike my PC that's kind of a horror show when you open it up after a year.

The inside of my PC must be dusted semi-regularly, along with the filters being cleaned, but I've pretty much just allowed the outside to collect dust for the past 2.5 years.

I can't say I've ever cleaned my 3DS, though...

I clean everything. My room, bathrooms, kitchens, dining rooms, living rooms, and so forth. Devices aren't an exception.

I clean the wii u and the tv for it every other day. I also do the same for my 3ds and PC.

Cleanliness is everything. I cannot stand people who are dirty and unorganized

I maybe clean my PC once every 3 years ?

It would be even more frequently for smaller devices though ...