I'd strongly suggest Time ATACs in some form. I've ridden the same set of ATAC cleats for 2 years, pretty much day-in and day-out, including all the grinding on the ground and everything. I've since replaced the shoes and cleats, but I only ever pulled out of the ATACs once, and that was after I had been riding the cleats in the "you know, this isn't really a good idea" state for about half-a-year -- my shoes were so worn that most of the time, I was literally walking on the cleat on flat, smooth ground.

All this is to say: get a pair of ATACs. They won't let you down, regardless of what you're riding in, and they won't let you go unless you want them to. (Additionally, I've not had any problems with clipping out)