Are there any nice looking and lightweight pedals meant to be used with or without SPD shoes? Would be nice to be able to ride even without my special shoes, but not if such pedals look bulky and heavy.
Shimano make several models of pedals with SPD one side, and flat on the other. So they can be used with SPD shoes or normal shoes. Options include:
These are designed for road/touring bikes, so are fairly slim, with a small metal platform. (Not to be confused with the PD-A520, which are one-sided SPD pedals, without a flat platform). Personally I use these, they work pretty well, with either SPD shoes or non-SPD shoes. Weight: 383g (pair)
Designed for trekking or commuting bikes, they have a larger plastic platform. So they look a bit bulkier, but are not actually much heavier. They have reflectors built in, which is useful if that is a legal requirement where you are. Weight: 392g (pair)
An older model, with a large metal platform, so a bit heavier. They have the option of adding reflectors or toeclips. Weight: 533g (pair)
Another vote for the PD-A530. In my case I have these on the hybrid and PD-A520's on the Cannondale road bike.
Both pairs are adjusted so that they feel the same so the muscle memory on both bikes is the same. In a panic stop, I don't want to have to remember which bike I am on to get out of it.