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.