Lets see how many gamerscores you have gotten on Gog! (feel free to add your own)

Collect them all! * 800
Get all games in a series

So bad its good * 500
Buy a game that is rated 2 stars or less

Thrifty * 1500
but 8 or more games during a sale

Opportunist * 1000
Grab a game when its free for a limited time

Nostalgia-tinted Glasses * -5000
Give a game a 5 star review based purely on the fact you loved the game when you were younger

Actually earned it * 3000
Give a game a 5 star review without succumbing to petty nostalgia

Thats a tough one * 500
Ask a question that goes unanswered for a week

Mind Melter * 1000
Ask a question that goes unanswered for a month

Question for the ages * 2000
Ask a question that goes unanswered for 6 months

Wishful * 300
Have 50 or more games on your wishlist

Lucky * 500
Have 3 to 7 games on your wishlist be on sale

Jackpot * 1000
Have 8 or more games on your wishlist be on sale

Good Semi-Old Game * 1500
Buy a game on GOG that was released after 2010

Indie Indeed * 1000
Buy an indie game

Hype Backlash * 500
Give a highly rated game 2 stars or less

Wait, people actually buy these? * 2000
Buy a GOG movie

Additions from HereForTheBeer

Meh * 500
Free game offered, but you you didn't take it

Been there, done that * 10,000
You got to go to GOG HQ, whether by invite or by just showing up outside their door to get a photo

Math is hard. :(

Let's see if I can remember, without actually looking at the library:

Collect Them All (Stalker)
Thrifty (Maybe? Possibly for a 'my library' / giveaway combo back in the day)
Opportunist (Not sure what you mean by buying a free game, but yes, I've snagged a few.)
Good Semi-Old Game (Easy one: Divinty: OS and TW3, among others)
Indie Indeed (Several)
Wait, people actually buy these? (Several)

That's 7,800, I think. Enough for an internet cookie or two.

I'd like to add:

Meh * 500
Free game offered but you didn't take it.

Been There, Done That * 10,000
You got to go to gOg HQ, whether by invite or by just showing up outside their door to get a photo.

Okay, I'll play:

Collect them all! * 800
Get all games in a series (Fallout games, among others)

So bad its good * 500
Buy a game that is rated 2 stars or less (Master of Orion 3)

Thrifty * 1500
but 8 or more games during a sale (done this a number of times, especially when I was doing giveaways)

Opportunist * 1000
Buy a game when its free for a limited time (oh, yes)

Thats a tough one * 500
Ask a question that goes unanswered for a week (yep, asked in one of the game subforums - don't recall which one now)

Mind Melter * 1000
Ask a question that goes unanswered for a month (as above - same question, actually)

Question for the ages * 2000
Ask a question that goes unanswered for 6 months (as above)

Wishful * 300
Have 50 or more games on your wishlist (yep, currently 83 games)

Lucky * 500
Have 3 to 7 games on your wishlist be on sale (yep, right now there are 20)

Jackpot* 1000
Have 8 or more games on your wishlist be on sale (see above)

Good Semi-Old Game * 1500
Buy a game on GOG that was released after 2010 (yep, several. Dragon's Dogma for example)

Indie Indeed * 1000
Buy an indie game (several)

I believe that's 11,600 if my math hasn't deserted me. Ooh, another 10,500 points for me! :P

https://www.gog.com/forum/myquestions

Scroll down to the unanswered ones.

My oldest one without an answer is this from 2012:
https://www.gog.com/forum/might_and_magic_series/mm3_five_altars_in_the_cathedral_of_carnage
(Well I did answer it myself but can't mark it as solution)

Oldest one with no answer at all:
https://www.gog.com/forum/might_and_magic_series/noams_hammer

Funny... I just clicked this "My Questions" link for the first time. Seems like I have a very special question with a whopping 0 answers.

screenshot (have a look at the "link" to the thread)

Maybe you'd have gotten more answers if the question actually had some content.

(seriously, though, looks like a thread that got deleted).