I use speedplay frogs on my road or mountain bikes... They're easy to get into and out of - lots of float for my knee. I had my share of clipless pedal falls in the beginning, but they're pretty 2nd nature by now.
On my commuter or bikes that I use platform pedals on, I use VP bear trap/cage pedals - you can get 'em on ebay in various fun colors, and you can hook toe clips to them (least they definitely have the holes to do it):
http://shop.ebay.com/?_from=R40&_trk...ar+trap+pedals