Computerbase.de compared 14 types of DDR400 Ram; Corsair, Crucial, Infineon, Kingston, Kingmax, OCZ, Samsung, takeMS and twinmoss were present. All were tested on an i865 motherboard.
The 21 page review marks Corsair TWINX512-3200LL and Kingston HyperX PC3500 as performance winners; Crucial and Twinmoss gain are the best buy.
If your German is good enough, and you have some spare time left, go here.