Of course the Intellivision's disc is more like a d-pad in that sense, but probably less functional as one than the CV controller is as a thumbstick (due to the somewhat slippery and recessed disc as well as the 16 directions), plus is at a less convienient location compared to the CV. (in terms of grasping the controller single handed)
And of couse there's the 5200, which might have been a pretty good configuration with a digital joystick (both as a thumbstick and finger gripped joystick), well that and better buttons. (ie larger, and less prone to wearing out -using ones more like the paddles or 7800)
But the key example of a gamepad like arrangement would probably be the vectrex, albeit that's with an analog thumbstick rather than a d-pad.
Edited by kool kitty89, Sun Feb 14, 2010 9:24 PM.