The first card, the GeForce 256 was launched in 1999, and was the most powerful consumer card at the time. This was later updated to the GeForce DDR, which held an even greater lead against its opponents. While the TNT2 line was still handling the mainstream, the first-generation GeForce sold respectably.
The GeForce 2 GTS was launched in 2000, and was generally faster than it's competitors - the ATI Radeon and Voodoo 5 5500. The real success story of this generation was the GeForce 2 MX, which (along with the MX200 and MX400) remains the top-selling consumer-level card of all time.
GeForce 3 was next in 2001, and in spite of outperforming it's competitors considerably, it never reached the consumer level and was the least successful GeForce generation.
GeForce 4 followed in 2002, and finally offered a viable alternative to the GeForce 2 line. In spite of the Radeon 9700 and 9500 outperforming it, they suffered from supply problems, and the GeForce 4 went on to be the dominating card in 2002.
The current line is the GeForce FX, and in spite of the failure of the initial models (the 5800 and the first revision of the 5600), it eventually became a viable and successful product line, but has recently come under fire for poor performance under DirectX 9.0 games.