Another vote for COD 4, even if I do get massacred every time I play online. Fallout 3 not in the same league but pretty excellent too.
Goldeneye probably was the best game ever when it came out, but simply isn't any longer. Other standout "of the time" best games would include GTA 3, original Metal Gear Solid (but they lost the plot with too many long cut scenes thereafter), Hungry Horace, Sensible Soccer and FIFA 99.