I like your standard, double-sided SPD pedals. They are easy to clip into, the shoes are easier to walk in, and the slightly larger pedal platform allows me to stomp on the pedals, with one pedal in the middle of my shoe. That way, I can get through the intersection as fast as possible, and worry about clipping in after I'm across the street and not potentially in the way of traffic.
That is the main reason that I did not like Look Keo pedals. They are more difficult to clip into, and if you miss clipping in and try to pedal anyway, your foot is very prone to slipping off the pedal like it is made of ice. SPD shoes are a little heavier, and not as stiff, though.
I've been thinking about trying speedplays the next time that I need pedals or shoes. They are double-sided, and the guys that I know with them say that it is pretty easy to stand and stomp-pedal while not being clipped in.