Getting one if the chink android emulator handhelds is probably your best bet for emulation stuff, you can get everything up to ps2 probably.
If you dont want to pirate or whatever, you can probablg find a used ps4 or xbox one. No free online doebeit and games/controllers will still come with a price.
Ps3 is a good choice for an older console. Online is free and a few games still have it like some COD titles. Games, at least in the UK, are dirt cheap and you can get most major titles for under £10.
The wii is also dirt cheap but has unconventional games. It can emulate up to n64, and is compatible with gamecube if you want that too.