I've been using SPDs for ages, but I tend to like the 'ski binding' type feeling. I totally lost it on a trail once with eggbeaters because I actually had to take 1/4 sec to make sure I was clipped in... I like how SPDs audibly let you know that your feet aren't going anywhere.

That said, the eggbeaters have lots of float, and are super quiet. You really do need some degree of faith to ride them though.

I've heard good things about Time ATACs. A buddy of mine would only run these. I've seen a few too many pieces of Time pedals strewn about on the trail though, so I guess when they fail, they explode?

Never had a problem with my Shimano A530s. They're not exotic, but damn solid.