This might fall out of line but the games that I really played a lot were Mario Party 1 and Pokemon Diamond/Pearl xD.
I just feel so nostalgic thinking about the time when my buddies and I would battle for hours playing this on our Nintendo DS lights.
Why would it fall out of line? Any game can be your favourite for a whole bunch of reasons! As long as you got great memories with it, its overall quality doesn't matter all that much. Plus to be fair, Mario Party and Pokemon are still pretty good games.
Since I'm commenting, might as well add some new games to my previous list, made one year ago.
-Max Payne: I'm usually not that much into story-driven video games, as the reason I'm playing is mostly to chill out. I also like to be able to hop quickly into a game, play a match, then leave. But Max Payne is nostalgia : I watched my grandpa play the first two games on his old computer and thus it reminds me a lot of him and how he made me learn how to love PC-gaming (he also played Age of Empires !) As for the franchise itself... I simply find Max Payne to be the most cinematographic game ever, that also happens NOT to be a mere interactive movie. A well-known French videomaker said that Max Payne the game is a better movie...than Max Payne the movie. And I agree with that. The film noir/hardboiled genres are perfectly recreated. I also love their creativity, mostly in the first game, with all the cutscenes being played by members of the team in that visual novel style. And obviously, the writing and voice-acting is top-notch. Max being one of my favourite video game character. Like most people, I didn't like the third game AS MUCH as the previous two, but I still find it great. It's nice that they took the gamble of going to Brazil (way before it was a meme mind you) and it still looks good too.
-Dead Space : I wasn't so sure to mention that franchise considering it's dead in the water and the third game I hated... But the first two are still among my favourite horror-based video games, and that's saying something considering I'm not very fond of those. Necromorphs are the perfect twist on zombies at a time when they were absolutely everywhere (plus I'm madly in love with Carpenter's The Thing, so it gets extra sympathy points). The game can also be bloody punishing as you crank up the difficulty. But the thing I'm the most proud of is definitely the atmosphere : very little music, except for some spine-chilling nursery rhymes... a pitch-black environment with very little room to maneuver. And a slew of monsters all more disgusting than the other. I still believe we don't have nearly enough dark sci-fi games. I personally didn't mind that the second game was more talkative (with Isaac being given a voice as well), but it is true that the latter half that gives you more ammo against more monsters should have been a fair warning of what was to come... Still, I find both games incredible. Managing to scare you without resorting to (too many) jumpscares and without making you powerless. Last but not least : I loved the small enigmas that reminded me a bit of the Half-Life series for how intuitive they were. The games were quite varied in the situations they proposed.
-Enter the Gungeon : I like many kinds of games. I mentioned I was a fighting game addict, but the same could be said about roguelikes (or rogueLITES for the purists among us). Yet for the most part, none of them were as rich, fulfilling, deep, fun and intuitive as Isaac was for me. Sure I loved Nuclear Throne, but it was just too easy to die in one-hit from a grenade and it was too action-packed for me. Sure I loved Risk of Rain, but the difficulty curve was often too big with that damn timer. Cue Enter the Gungeon : a game I closely followed up until it released, watch lots of people playing it... Then forgot about it for years to come. It is only when the Epic Games Store proposed it for free that I finally gave it a go. And boy, did I do well ! In my opinion, it is the perfect bridge between Binding of Isaac and Nuclear Throne : it is much less luck-based than Isaac (where even a new player could do fairly well with great luck, and a veteran could die quickly if he got shitty items), but also less straight-forward than Nuclear Throne (you can survive for longer and actually have some items that are more strategic than MORE DAKKA). I also find the game to be much more skill-based, as you need to master the dodge-roll and the reload way more. I also love how far they went with the "bullet lore" : with every opponent being linked to weaponry and the amount of wacky weapons (and synergies !) being astonishing. It also takes ages to complete everything, as any good roguelike should. I'm just a bit bummed that after two (or three?) very large updates, they jumped the ship. I would have loved a few more characters and bosses personally, but that's nitpicking. And that's what the mods are for I guess... I'm a bit bummed that they quit development on Enter the Gungeon only to offer... Exit the Gungeon, which is pretty much more of the same thing.
-Madworld : Wasn't so sure to include that game at first, but considering it's my favourite Wii game, the one who pretty much kickstarted Platinum Games and one I just can't stop mentioning at random... I guess it's only fitting. Madworld is stylish in more ways than one : the Sin City-like aesthetics are awesome, it's absolutely bonkers, it's funny as hell, the gore is excessive but always in a cool more than a disgusting way, the characters are insane, the music is pumping... Really, I struggle to find a lot of others games that are just oozing with coolness, without trying too hard that is. I also felt the Wii Motion controls to be quite intuitive and mad fun, in a sadistic way. I wish more games actually used it similarly (although you surely looked dumb while doing so). The story itself is a bit bland, and Jack Cayman is quite cliché as a "take no ****" protagonist. But that's pretty much it. The difficulty is well-balanced, the situations you ends up in are very versatile (and so are the methods of killing people) and I think I can still name every bosses to this day... With the "Bloodbath Challenge" music still ringing in my brain.
-Killing Floor 2 : I really wanted to put Doom instead, but I had to give credit where credit is due. I played KF2's beta, meaning it's one of the only games I ever preordered (along with Borderlands 2 and Binding of Isaac Rebirth). I played for nearly 500 hours. I'm closely following every updates and I've been commenting on these forums for like... five or six years now? So it would be unfair to dismiss Killing Floor 2, although it has become a game I love to hate and hate to love. Sure it doesn't excite me as much as it used to anymore. Sure I feel like I did everything that was worthwhile and thus probably won't play it all that much anymore. But very little things beat the sheer fun of playing with friends and making it through the end on Sui/HoE. Trying new daring loadouts and/or team comps has become my main experience on Killing Floor and it's sometimes incredibly fun, even if rarely effective. And while I lament what the game COULD have been, I still can't forget that back in the day, quite a few things made me crazy : the numerous QoL changes that prevents me from crawling back to the first game, the gore-system that wowed the SHIZZ out of me (even today, I believe only MK11 and Left 4 Dead 2 can match that level of gore), the new perks, some of the new weapons that were as daring as they were exciting, and even the seeds of lore you planted... only to nooot really expand on them. Yeah, that's true, many things I would have done differently. But it is not MY game, and yet I played a lot. And as I said quite a few times : I wouldn't be still commenting on these forums if I didn't care deeply. And I don't think I ever done so for any other game. Not even TF2 back in the day.
(I should probably make a specific list regarding fighting games at some point to be fair...I realize Soulcalibur 2 simply isn't enough, and I just don't want to have half my list filled with them)