Another vote for Crank Bro Candys. It's the same as the eggbeater, but with a little bit of a platform, which is nice (and not that much extra weight, if you're worried about that). The best thing about Crank Bro pedals is that you have some float. At least more than with SPDs. I used to have SPDs and my feet would go numb after a lot of riding since you don't have much wiggle room. With the Crank Bros you can wiggle a little. In any case, my feet are comfy for long rides and don't get numb. And I have NEVER unintentionally came unclipped with them, while skidding, skipping, anything.
Also, you can get their "smarty" pedals for less money, if you are on a budget. It's the same clip-in system, but they are only slightly heavier and a lot less expensive (I saw them on sale at Performance for like $39).
** and you don't have to clean or service them, even if they get all muddy. The dirt just dries and comes out itself.