Crank Bros. Mallets or Shimano M545s. Both have big cages so you can wear regular shoes. I've used both and currently have the Mallets. SPDs require setting a tension screw while CB's use a spring to increase tension as you pull up, but unclip easily if you twist out. If you over do it on the SPD tension screw, twisting out can be difficult. Too lose and you'll unclip unexpectedly.