A lot of people already discussed hardware and longevity with you, so ill try to talk about other things.
I'd go with PC because:
- Mods are incredible, to the point where if you like a specific genre thats very modeable, such as strategy games, you can literally get hundreds of almost new games for free. It can make your favourite games unlimited in content, seriously.
- Many more games and more variety, In this aspect the PC is huge compared to consoles. Also the most unique and original games always come in PC.
- Games are much cheaper in general.
- You can choose between visual quality or performance. This is very important, if in a game you dont care much about its graphics you can get it running extremely fluid and trust me, it really makes a difference, also you can sacrifice lots of almost unnoticeable or even ugly effects for the nice things you like the most.
- Good old times. With a PC you can play very very old games from the best times in gaming, and if you also had a PS1/2 Gamecube or some others, you can use your games with emulators, and at this point they work in general very very well.
- You can use a gaming PC for video editing or many other things.
- Its upgradeable, so whenever you want a bit more power in the future just buy one part, and not an entire new machine.
- Mouse and Keyboard are much superior to controllers for almost ANY game where you have to move the camera (first person shooters and third person games).
- Tons of free games and many are pretty good, if you want quick fun without spending money.
There are other things of course but i feel this is enough.
Good luck with whatever you choose.