Probably already mentioned, but if not (looks like it was. 6 replies prior to my post... )
GeForce FX 5900 Ultra. The Radeon 9800 Pro/XT was killing it in everything. Benchmarks, gaming, you name it. The FX series was one of NVIDIA's darkest moments.
Presler XE from Intel. The 955/965 couldn't beat cheaper Athlon 64 X2 processors in FPU operations. AMD surpassed Intel in the retail market at the time on the Athlon 64 X2 product line.