I think the DS Lite D-pad is atrocious. Really, it's a disgrace, I can hardly believe they didn't change that and the shoulder buttons on the DSi. Mine's pretty crappy right now, and it's the reason why I stopped playing it for a while.
And Soma Bringer was so fun... ):
GC and X360 also have really bad D-pads, but most of their games use the analog stick, so that's not that big of a problem. The DSL, on the other hand, not all games can be played exclusively on the screen.