I think that my favourite game of all time is Counter Strike. I really have spent a lot of time in Counter Strike 1.6 and from recently I got into the Global Offensive one. I was playing CS 1.6 since I was 8 years old and still enjoying it but not that much as CS:GO.
The three games I’ve had the most fun playing were Legend of Zelda: Ocarina Of Time, COD MW2, and COD BO3. I skipped all the COD games after MW3 because they got really boring and repetitive. BO3 was finally something that felt like something new, but kept the same COD feel. Most people probably wouldn’t agree with me on that though.
Oh man, this is a tough question to answer. I think it'd have to be TES: Skyrim. Although I've played it too much and keep getting bored of it, I always find myself drawn back to it. And, of course, there's thousands of mods to keep spicing the game up and changing it completely.
I could post a huge list of games that I consider my favorites, but that would take all night. So instead I'll just post some of my top favorites.
NieR: Automata - This game might actually be my #1 favorite game of all time. Everything about this game is just amazing. The story, the characters, the combat (thank you Square Enix for finally getting Yoko Taro some help and actually giving him a budget), and some of the best music you'll ever hear in a game. There isn't much that this game doesn't do amazingly. Obviously no game is perfect, but this might be the closest to perfection that any game will ever get.
Utawarerumono: Mask of Deception & Utawarerumono: Mask of Truth - My two favorite Visual Novels that I've experienced so far. The reason these game are listed together is because they are basically one game cut in half. Mask of Truth picks up right where Mask of Deception leaves off and continues the story as it was. It's not a case of there being a 10-year time skip between the two, so I list them together. These two games are the main reason why I only said NieR: Automata might be my favorite game of all time. If it's not Automata, it's these two. Amazing story, amazing characters, beautiful artwork, gorgeous music, and a surprisingly deep battle system. I don't think I've ever seen a story as good as this in another game. These games are must-plays for any Visual Novel fan (especially if you like a little bit of SRPG gameplay to go along with your Visual Novel).
Dark Souls - This is one of those games that I could play over and over and over again for tens of thousands of hours and never get tired of it. It's the game that made me realize just how bad Skyrim is, and saved me from wasting any more time on that game. Definitely one of my top games of all-time.
Dragon's Dogma: Dark Arisen - This was the other game that saved me from the terribleness of Skyrim. Dragon's Dogma has such fun combat, and one of the best bow mechanics out there. I love using bows in games like these, and this game definitely delivered on that front.
Star Ocean: Till the End of Time - The Star Ocean game that began my love of the series, and the one that I've pumped the most time into. This is another game that I could play over and over again and never really get tired of it. It has definitely aged since the PS2 days, but I still love it dearly regardless.
Tales of Vesperia - What's not to love? Best Tales game by far. Can't wait to play the remaster this winter, especially since it'll be the first time I get to enjoy the PS3-exclusive content that the west never got.
Final Fantasy Tactics - My favorite Final Fantasy game along with IX, and one of the best SRPGs out there. Has by far my favorite story of any FF game, and has some great music to go along with it.
Final Fantasy IX - My favorite of the numbered FF games (and the best one overall). Has that good turn-based combat along with great mechanics. Music is pretty great too. Thankfully a return to learning skills off of equipment. The only thing this game really did wrong was Tetra Master. Triple Triad in FFVIII was so good, but then they just failed on replicating that greatness with Tetra Master. Other than that, by far the best numbered FF game.
Super Mario RPG: Legend of the Seven Stars - When people talk about SNES RPGs, you always hear them talk about Chrono Trigger and Final Fantasy VI. Those games are good and all, but let's not pretend like they are the best RPGs the SNES has to offer when this gem is around. The only big negatives this game has is how short it is and how easy it is, but then again neither Chrono Trigger nor Final Fantasy VI can boast about difficulty at all either, since both are just as easy. They do have length over SMRPG, but other than that, SMRPG has them beating. Square Soft really outdid themselves with this one, taking Nintendo's most iconic series at the time and turning it into a turn-based RPG.
I could keep going, but I think this is enough for now. Maybe I'll go through and list some more of my favorite games another night.