Jet Set Radio and no way in hell. It felt like lightning in a bottle. No game has ever had more style, substance, and a killer soundtrack to boot. It's perfect.
This. Though for me it is a tough battle between JSR, Crazy Taxi, Skies of Arcadia and Shenmue 1/2. The mixture of nostalgia, personal impact of those games on me and my taste in gaming and allaround that time being a special time for me will make it difficult for those gems to be beaten.
The difficult thing is, I don't really have one single favorite game, just different games in different genres where I think those games were the peak for me personally.
All my favorite games on an objective basis will be dethroned at some point - and this already happened with NES to N64 favorites of mine. As I got older, I found that around 30 I started to see games in a fresher light again and started to enjoy gaming more again. Last 3-4 years were the best years in gaming for me since late 90s/early 2000s and I think this had a lot to do with me changing my point of view and being able to see new things with the same enthusiasm as I saw them when I was still a teenager. Both new games and classics I've missed out on.
Which brings me to the point that I could make an argument for Zelda BotW being the best, most magical gaming experience I've had in a long time.
The Trails in the Sky/Cold Steel series might have dethroned Skies of Arcadia for me, in a way. Also, while fundamentally different games if you look closer, Yakuza Zero really gets close to Shenmue, also thanks to the 80s setting.
And, while it started out as a "this is OK, but so what"... Metroid Prime over 15 years went on from a game I felt was overhyped to a game I replay every year to a game I really adore.
There really hasn't been something like Jet Set Radio/Future ever since, though, and I still replay JSR 1-2 times/year. I think this thread made me realize that I could make good points for JSR being one of my most beloved games and at the same time it is highly unlikely that it will be dethroned since ... there's no way to really capture that essence of the era again.
Also, this thread makes me want to finally check out Dark/Demon Souls.