Wow, I haven't even posted in this thread... Er I am so not sure about my picks, but here we go:
1. The Sims 2
2. Final Fantasy 6
3. Mass Effect
4. Portal 2
5. Elder Scrolls: Skyrim LOL
The Sims 2 particularly with mods allows for so much creative freedom and I love that a family line can continue on for generations. I have more ideas for the Sims 2 than I have time to play. I didn't really like Sims 3 too much and Sims 4 still doesn't have toddlers, so I'm sticking with 2, have played it more than any other game, and just fiercely love it. Even the music is great
Final Fantasy 6 is my favourite FF, tho I have to say I no longer have the patience to replay it for all the grinding. But to me it has a very engaging story, great characters and amazing music. Even the combat can be quite fun because the characters have such different skills. I think this is how a game with multiple character story arcs and unique skills should be made; ideally I would just make it less grindy.
Mass Effect is here because it's one of the games along with Portal that got me into this newer gen of PC gaming. I felt like absolute boss playing as female Commander Shepard and I basically learned a new type of combat because I hadn't really played a game like this before that I can recall. Mass Effect 2 is likely the better game, but I haven't played it as much so I didn't feel comfortable putting it here. But man, Mass Effect - I spent hours riding around planets on Mako because I didn't want to miss anything. I was obsessed ha ha.
Portal 2 I wanted to put here because Portal was sort of important to me in getting into 3D world games and Portal 2 is like Portal, but better. Well, better as in it has more varied gameplay. I've even had some fun replaying it even if you might think that replaying a puzzle game where you sort of know all the answers (I can't remember everything though) wouldn't be any fun.
Skyrim with mods especially... I don't know why it feels silly to include this game here, probably because people shit on it so much online
But I've spent so many hours on it. I loved that I was able to play it very far (past the main storyline) with conjuration magic where I'd basically have two conjured allies + a follower doing all the fighting for me while I'd sit back and loot or whatever. But then that save file got fucked up when Steam did that paid mods BS experiment, thx a lot. I've heard that, for instance, earlier games in the series do some aspects of varied combat better, but I've had fun on Skyrim experimenting with things, and only now I'm doing the most common variation which is a sneak archer
I've also had interest in roleplaying in the game, and there are lots of mods that make that more interesting. Basically Skyrim is like Sims 2 in the sense that there is so much freedom with what you can do with it, especially with mods. But even without them there are different ways of doing things and you can basically ignore the main storyline etc. The game's far from perfect, but yeah, it's fun!