I've been using Eggbeater SLs (I'm a big fan of stainless) for commuting for a few years now. I just put a second pair on my touring bike (although I'm thinking about the Cs for a little more support over long rides). They've held up really well so far. Easy to clip in and out of and very little spring tension in the float. Another good choice would be TIME ATACs I used them on my mountain bike for quite a few years and had good luck with them, although my preference is for the eggbeaters. I've never ridden Shimano pedals so I can't say much one way or another.
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2009 Bike Friday Season Tikit (commuting folder)
2007 Rivendell Atlantis (touring, general riding, errand runner, stuff hauler)
2007 IRO Mark V (SS)
2006 Rockhopper Comp Disc (Icebike)