I love threads such as this. Some of these might not seem too vague to some of you, but many of them depend on your age:
Space Station Silicon Valley (N64, 1998)
This is on my short list of favorite N64 games of all time, probably up close to Zelda OoT and Super Mario 64. It's that good. It's wickedly irreverent, ingenious in its premise, and actually funny. It looks cute but the premise of the story is slightly less: you are a parasitic microchip, and you have to implant yourself in dead animals and possess them to survive. Each of these animals have different traits. The sheep is the most lame, but somehow I remember it being able to fly/float or something of that nature. Bunnies could only hop, elephants were slower than molasses, etc. All tons of fun. If you have an N64 and you want to play something on it, get this. Immediately.
Pocky and Rocky (SNES, 1992)
An incredibly cute game that plays rather like SNES Zelda games. The difference is that two people can play at once. Pocky's a kid, and Rocky is some type of raccoon dog thing. They can fire a ranged weapon, or attack melee-style. It's really simple, but a lot of fun.
Okami (Wii, 2008)
This game is excellent, but sadly almost completely neglected. It's by Capcom, which usually brings up some red flags for me, but it plays very similarly to Zelda, which is a definite plus. The gist of the story is that you are Ameterasu, the Shinto goddess of the sun, and you have to save ancient Japan from ....something evil. It's done in a really cool-looking Japanese woodblock print style and the gameplay is really entertaining. As I said, almost completely neglected. The upside? I got it for $25.
Fat Princess (PS3, 2009)
It's really funny that the game I find most entertaining on PS3 is ridiculously simple. It's all team-based, online play, and the point is this: you have to rescue an obese princess from another team's castle, all the while protecting your own princess from the other team. You can feed your princess cake, which will make her harder to move by the other team. You can play as five different classes (ranger, cleric, mage, warrior, builder, I think, I usually only play as a mage) and *gasp* you have to work as a team to get the Princess back to your castle. Did I mention that it's incredibly bloody? :)
Tanks (TI-84, ???)
I wasted so many hours in my calc class playing this dumb game. It's essentially what it sounds like: you are a tank, and you blow up the other tanks. It is, however, brilliant.
Baldur's Gate II (PC, 2000)
The last great PC game of the millennium. You might be reading this and thinking that it's not obscure enough, but I've come across too many "gamers" who have never heard of it. To make a long story short, you play a Bhaalspawn, an offspring of a dead god of murder named Bhaal. The game is c. 2000 graphically, but eons ahead of many more recent games in terms of gameplay and depth of storyline. The addition, Throne of Bhaal, was decent, as well. In my opinion, the best D&D game for PC. By far. Play it; it will consume your life.
I'm sure there are others that are just slipping my mind, so I might update later.
Space Station Silicon Valley (N64, 1998)
This is on my short list of favorite N64 games of all time, probably up close to Zelda OoT and Super Mario 64. It's that good. It's wickedly irreverent, ingenious in its premise, and actually funny. It looks cute but the premise of the story is slightly less: you are a parasitic microchip, and you have to implant yourself in dead animals and possess them to survive. Each of these animals have different traits. The sheep is the most lame, but somehow I remember it being able to fly/float or something of that nature. Bunnies could only hop, elephants were slower than molasses, etc. All tons of fun. If you have an N64 and you want to play something on it, get this. Immediately.
Pocky and Rocky (SNES, 1992)
An incredibly cute game that plays rather like SNES Zelda games. The difference is that two people can play at once. Pocky's a kid, and Rocky is some type of raccoon dog thing. They can fire a ranged weapon, or attack melee-style. It's really simple, but a lot of fun.
Okami (Wii, 2008)
This game is excellent, but sadly almost completely neglected. It's by Capcom, which usually brings up some red flags for me, but it plays very similarly to Zelda, which is a definite plus. The gist of the story is that you are Ameterasu, the Shinto goddess of the sun, and you have to save ancient Japan from ....something evil. It's done in a really cool-looking Japanese woodblock print style and the gameplay is really entertaining. As I said, almost completely neglected. The upside? I got it for $25.
Fat Princess (PS3, 2009)
It's really funny that the game I find most entertaining on PS3 is ridiculously simple. It's all team-based, online play, and the point is this: you have to rescue an obese princess from another team's castle, all the while protecting your own princess from the other team. You can feed your princess cake, which will make her harder to move by the other team. You can play as five different classes (ranger, cleric, mage, warrior, builder, I think, I usually only play as a mage) and *gasp* you have to work as a team to get the Princess back to your castle. Did I mention that it's incredibly bloody? :)
Tanks (TI-84, ???)
I wasted so many hours in my calc class playing this dumb game. It's essentially what it sounds like: you are a tank, and you blow up the other tanks. It is, however, brilliant.
Baldur's Gate II (PC, 2000)
The last great PC game of the millennium. You might be reading this and thinking that it's not obscure enough, but I've come across too many "gamers" who have never heard of it. To make a long story short, you play a Bhaalspawn, an offspring of a dead god of murder named Bhaal. The game is c. 2000 graphically, but eons ahead of many more recent games in terms of gameplay and depth of storyline. The addition, Throne of Bhaal, was decent, as well. In my opinion, the best D&D game for PC. By far. Play it; it will consume your life.
I'm sure there are others that are just slipping my mind, so I might update later.