I've used everything you've mentioned as far as clipless goes. They each have their pros and cons so I'm not going to try and recommend anything in particular. I will say that SPD-SL is a road pedal and typical road shoes are pretty stiff so even the ones with some tread on the bottom aren't very nice for walking in. Commuters tend to shy away from those and that's one reason.

Discussions about clipless pedals come up fairly frequently and there's no real consensus over which type is better or whether or not they offer a significant advantage to commuters. Some folks really like them and others are happier with plain old platforms or toe clips.