Gran Turismo 3: A Spec (to give GT3 it's full, Sunday name).
To say this is a favourite of mine is an understatement. I'm fairly sure that this is, by far, the game I have played the most in my life. I really loved the first two games in the GT series, but this was a complete obsession for me. I got it on release (the day before, in fact. Someone who used to work for me went to Sony to be an assistant producer on it, so got me a copy early) and played it almost exclusively for years. And if I wasn't playing it, I was on various forums reading and talking about it or reading FAQs, finding new tunes or devising new strategies to get as far I'm with minimal effort...
I've recently played the first two in the series. The first one was a technical tour de force, but there actually wasn't a lot if game there and it wasn't a lot of fun to play - the handling was amazingly twitchy, there weren't many events which meant you had to grind to progress and the AI was just A. GT2 improved on the game-ness with lots (and lots and lots) of events, with a decent competition structure that allowed a proper progression. Still a bit grindy, still crap AI, still stupidly twitchy.
So, to the first of the PS2 iterations: GT3. For me, this was the pinnacle of the series. I'm sure someone will tell me 4/5/6/Sport is better because reasons, but this was just spot on as far as I am concerned. It vastly improved the handling, though it leans much more towards understeer now. Fiddling with the car set up improves this a lot. The competition structure is a big, big improvement and hasn't really been bettered IMO: you get a lot of the same events, with stipulations like Mercedes / Audi / Mitsubishi Evo only, FWD only, Type-R only, across multiple race length and difficulties and a mix of single and league events. It's also quite generous with the prizes, so the grind is sufficiently lessened to the point where it vabishes, if you know what you're doing. It has a load of fantastic tracks that are a lot of fun the race on. The rally events could be a game on their own, they're that good. And the graphics, oh the graphics. I know "PS2 era" is an insult, but this still looks amazing.
It's not without its faults. The AI is still dumb as dogshit. And it sometimes resorts to straight up cheating to ramp up the difficulty. There's also the problem that you can spend to win - there's no restrictions on things like horsepower in any of the races, so you can bring a metaphorical gun to a knife fight. The lack of car damage also means you can wall ride instead of actually going around corners or us AI cars as emergency brakes.
I find myself once more fully hooked. I picked up a save from a game I started a little while back (the early part of the game is where I find the most fun) and found myself planning my next steps while I was driving to work this morning.
I need to find the power supply for my wheel...