These aren't in any particular order.
Earthbound
My favorite game of all time. It's the only RPG where grinding is actually fun, at least to me. That's because of the gameplay, it's just really fun. The story, however, can be crap at times. For example, after you get out of the spooky neon place, the story halts and you need to go in a monkey cave. The characters are memorable, but they're pretty bland. I'm assuming it's to reflect your own personalities on them but I have no idea.
I hate monkeys and this game loves monkeys aghMother 3
A lot better in Earthbound in many aspects (but I still like Earthbound more), for example, the story isn't crap. There's character development, instead of just "oh this guy's Jeff he's smart he fixes stuff ok." Same gameplay as Earthbound with minor tweaks, but grinding sucks in this one. Also note that the reason I didn't just say Mother/Earthbound Series is because I think Earthbound Beginnings is boring, with all of it's grind just to not get assaulted right outside your house.
Yume Nikki
This game gives me feels. You explore this girl's dreams, and collect thingies and then you kill yourself. Happy. The music is really short and looping, yet it fits so well. Exploring and finding new stuff is always cool, however since I love this game so much, I know every nook and cranny, so everytime I play, which is once in a while, I basically just look at everything again.
LSD Dream Emulator
This game is a lot like Yume Nikki, where you explore dreams, but it's 3D and very Japanese.
Very Japanese. This game's music is pretty sweet too, however, each area of the game has over an hour of different music tracks it can play. I uploaded all of them on my channel, and that took forever. Unlike Yume Nikki, you don't collect stuff, you just look at stuff. However, that stuff is random and more crazier per dream, since there are 356 days that you can play. The variables in this game are insane, I swear.
Half-Life Series
Perhaps the only FPS games I like (I should probably expand my horizons but nah). Every time I play one of the games, it feels like I'm playing it from the first time again. Not many games really give me that vibe. I am also one to take my time, I look at posters and stuff, admire the scenery after I've murdered lots of people, and I don't mind the cut scene heavy chapters. Also epistle 3 made me sad. Very sad.
Black Mesa
Although I said the Half-Life series was the only FPS games I liked, this is still Half-Life 1, just in prettier paint. That's basically it, other than the fact it's in Source. They improved a lot of things that bugged me about the maps in the original, for example, there aren't random blank corners, thy have purpose now. Very enjoyable, and I can't wait for Xen.
It's release date in when Half-Life 3 actually comes out not in epistle form.Garry's Mod
I have spent over 500 hours that I won't ever get back into this one game. It's really fun just to screw around, especially when I play with my sister. Not much to say really, other than the fact it's a pain to animate with. I also have a ton of workshops items that I (admittedly) don't use very often. I'l have to clean it out at some point but I'm basically a add-on hoarder.
Blockland
I've probably spent more hours in this game than any other on this list I can't tell though because Steam only records since I actually added it to my Steam. This game has inspired me to build and create so things, and it's been inspiring me for 6 years now. Whether I'm playing the normal version or v20, this game is just so enjoyable. I'm also a add-on hoarder here too...
Universe Sandbox²
Another game I've wasted a lot of time on. It's just a simulator that simulates gravity, but once I start, I almost cannot stop. Smashing Earth into Jupiter or creating my own Solar Systems never gets old, especially with frequent patches. Downloading and viewing other people's Solar Systems is awesome too.
Jazzpunk: Director's Cut
This is a weird one (well not really if you compare it to almost everything else on this list), but it is really good.
The comedy is great (in my opinion) and the areas you visit are each memorable and a blast to explore. There are a whole bunch of, side quests I guess? You can interact with almost everything in a map and something weird will happen. For example, you can steal money from a guy playing a saxophone, and then you can put it right back in, and he'll thank you. I have no idea why I find that so funny.
