Some of the basic favorites:

Super Mario

Donkey Kong

Spyro

but if I had to bring it down to one, Id say Final Fantasy X. 

Oblivion, no one can even blow the dust of this game. 

If you did not play it, your life has no meaning. Sorry! But everyone should play it once or at least watch gameplay and enjoy it, it's a on old game, but I am 100% certain there are some HD repacks and stuff. 

This is probably way different from most answers, but for younger people it is difficult to imagine the excitement of the old arcades where you would dump quarters into a machine until your weekly allowance was gone. Donkey Kong was my favorite.

Currently, Baldur's Gate 3. I've played it four times over and planning to play a fifth time too. I recommend if people like rpg/dnd !

Reading through recent posts and made me realize. The Crash Bandicoot series were some of my favorite games also.

Man, General Zero Hour... that game is just pure awesome. The way you could build your base, roll out your tanks, and just dominate the battlefield? Still gives me chills. Loved playing as the GLA and just being a total chaotic force. Best RTS ever, no question

I am a big fanatic of the resident evil series. Although some of them were not as good as the others I am looking forward to seeing some fresh ideas from the creators.  There is a fan offshoot being made called echoes of the living which has been postponed a few times. I cannot wait for its release it goes back to the original resident evil camera angles and such.

The best game I ever played is GTA Vice City. I was soooo consumed with that game. It's very annoying that our TV's got so big because if you hook up the game (through a PS2) to the TV now the quality of the game is terrible. That said, so many good memories to that game.