I like my sidewinder X6. I have had it for about 3 years now. I have abused the hell out of it, and it is still in great condition. There are also a lot of cool features built into the board, like macro programming and such. I have definately gotten my moneys worth out of it.
Oh, and I really liked the fact that the number-pad is magnetically connected. When I am not using it I get it off my desk. and you can put it on either side of the keyboard, making it an instant macro pad. its cool.