Grim Fandango is set in a stage between death and the afterlife. The game has four parts, with each happening on the Day of the Dead in sequential years (thus the music is part Mexican, part Jazz).
You play Manny Calavera, who must have been rather bad in life, because he has to spend several years selling tickets to the afterlife to the newly deceased. What ticket you get depends on how well you behaved during your lifetime. The best option is a "Number 9" ticket, which basically is for an express train that takes minutes, while the worst thing is a walking stick and you have to journey 4 years on foot.
After he sends out poor Mercedes Colomar on foot although she should have gotten a Number 9 ticket, Manny finds out that someone seems to be stealing those tickets and he tries to travel after Mercedes to save her.
Due to the setting there are a lot of strange jokes, e.g. because they are already dead, people don't get shot, they get "sprouted", i.e. they are shot with a special gun and then flowers start to grow.
The controls are a bit like in the old Resident Evil games (without the fighting; sprouting only happens in cutscenes).
Since I played the German version, I'm not sure about the voice talent in the original one. But despite German versions often having shitty voice tracks, this one was spot on, with the German voice of ALF as Manny. The music is mostly excellent.
I don't care much about the controls (would have preferred a point-and-click interface), but you get a strange, yet compelling background, interesting characters, and a story mix of fun and mystery with a slight love story thrown in.
If you need more information and a different take, read
this review.