Another vote for SPD road -style pedals like the A520 shown above. Shimano also recently released a better model, the A600, which they say is Ultegra-level - It gives an even larger platform and is slightly lighter than the A520 but is otherwise similar.

If I was racing seriously then I would consider using road shoes and pedals. Since I'm not, I cannot see any advantages of them and will stick with MTB-style shoes because I like still being able to walk when off the bike, plus having the same shoes work on all of my bikes is more convenient and cheaper than having multiple pairs.