I have ridden on almost all of Shimano's SPD pedals intended for mountain bikes, although I use them mostly on the street.

I have found the inexpensive double-sided PD-M520 pedals equal in usability and reliability in comparison to the very expensive PD-M970 pedals, except for weight.

You can get the 520's for about $50 and the 970's for about $180:

http://www.bikesomewhere.com/bikesom...duct/9/27/1026

http://www.bikesomewhere.com/bikesom...uct/9/27/19641

Try the 520's first.

As an alternative, Shimano makes a mountain bike pedal that has a conventional platform on one side and an SPD binding mechanism on the other side (PD-M324), and this costs about $85:

http://www.bikesomewhere.com/bikesom...roduct/9/27/44

I tried the 324's on my ice bike for those situations where I thought I might want to get free of the pedals even quicker than SPD's would allow.

It didn't work too well because I had to devote too much attention to which side of the pedal I had under my foot.

Again, try the 520's first.

All of the Shimano pedals I listed above work well even in the mud and ice and snow.