I have a road bike and a hybrid. They ride quite different from each other. My road bike, a Specialized Allez, has very skinny 700x23c tires and tall gears. Its drop bars allow me to get into an aero position when riding (especially in the wind). I also find I am more efficient when pedaling off the saddle (standing and pedaling). The hybrid takes the bumps of average to poor road conditions better than the road bike. While it isn't as fast, the difference is quite small for me when commuting, due to stop signs, traffic, etc. My hybrid has a flat handlebar, which helps with control, but doesn't offer as many possible positions as drop bars. Wind has a greater impact on my ride on my hybrid than on my road bike. I have a rack and fenders on my hybrid, making it an ideal commuter. I could add a rack to my road bike, but haven't found one that would go with the style of the bike.

If I could only have one of the bikes, I would probably go with the hybrid, though I really getting out on the road bike, too.