Since nobody has mentioned them yet, I’d encourage you to at least take a look at Speedplay pedals. They’re two sided, making them about the easiest pedals I’ve ever used to get into and out of, and you can choose how much “float” they allow (i.e., how much you can twist your heels side to side freely without clipping out). They do pretty well in dirty conditions, though they can get jammed up if you go tromping through clay. In those cases (e.g., Lake Anna!), I’ll just carry my shoes to the pavement and then put them on before hopping on the bike.