Depends on the game.

If it's a game that I am hyped for or a multiplayer game, then I'll buy it on release. Heck sometimes there are deals that allow me to get $20-$30 off of the pre-order prior to release.

If it's a game that I am meh about, I'll wait for it to go on sale.

I have spent $640 on games this year.

Nearly all of the games I buy were discounted. The only exceptions were Bayonetta 2 and Super Mario 3D All Stars on Switch for which I paid MSRP.

Almost always discounted.

Retail games between 30-40eur and downloadable games for at least 50% discount.
Only game that broke the trend this gen was BotW at the Switch's launch, and even bought that for 50eur.
EDIT: Wait, I deleted it from my memory, but got another outlier, and a digital game at that...
Also bought 1-2 Switch digitally around launch at full MSRP price thanks to the eShop.

BONUS: Spent over 200 euros in 2020 (normally it is around 300 for me).

I almost always wait for a discount unless the game costs like 20€ at launch, then I sometimes buy for full price.

Patience is one of my virtues.

Edit: backlog is the other.

Full price for physical games, they aren't officially sold here so we rely on imported versions

In reality grey market is now selling Switch games for 70, 75 and even 80 USD

For digital I generally wait for discounts. There are exceptions when I just can't find physical, then I buy full price

Edit: Spent around 670-690 USD this year on softwares

I pay what it costs at the moment that I want it. I guess it's usually MSRP or above thanks to super mega special editions. That's for my highly anticipated games at least. For less anticipated games I usually wait until they are more than 50% off. I would never buy second hand or from a key reseller.

I genuinely can't even remember the last time I bought a game at launch. Maybe Final Fantasy XIII? I pretty much always buy games at a lower price than MSRP. Haven't really kept track on how much money I've spent this year on games. Somewhere between 200 and 300 euros probably.

Nintendo games I almost always get at full price. One, because I really want them. Two, because they go down in price the least.
As for the others? I get some at full MSRP, but tons at discounts. I think the last games I got at MSRP were Spider-Man: Miles Morales and Spelunky 2. One of those is $49.99, the other is $19.99.

Rarely do I buy a game on release date. This year I've only bought like 3 games at launch.
Mostly, I buy games during sales.

Bonus: I think around $500 USD, give or take.