I've been a fan of pedals with platforms on one side and SPD on the other for years. I've used the Shimano PD-M324 Pedals, among others. I really like that for bikes that I tend to ride both for exercise and for transportation. Although if a bike is going to be used only for mountain biking or fast road rides, I'd probably go with a more specialized pedal. For mountain biking it is especially nice to have a clipless pedal you can click into from both sides.

I just bought a used road bike that I'm going to set up for fast rides. It's a lugged steel frame that came with the wheels and some other parts... including some old Campy pedals with toe clips and straps. I used to ride these exact pedals in the 1980s before I switched to clipless. Now I'm afraid of them! When I used clips and straps regularly I was used to reaching down and loosening the strap so I could pull out at a stoplight if I needed to, but with clipless I'm used to just twisting my foot to disengage the pedal. I could see myself forgetting to loosen the straps on these and just falling over at a stoplight. Of course it's unlikely I will find old road shoes with the slots for these old pedals anyway...