Their is debate about this among car buffs, but basically a heavier car will do better with more torque and a lighter one will want more hp. The gearing is a major factor as to which is faster. A car with a lot of torque can get by with mild gear and will have a broader power band. A car with a lot of HP will generally have a smaller power band and need low gears and a manual transmission to keep the car in its power band.
In a nutshell torque requires a large displacement motor (heavy) and hp compromises driveablilty (no low speed power). For example a motorcycle has a lot of hp and a 18 wheeler has a lot of torque. If you swapped motors the diesel motor would crush the motorcycle, and the motorcycle motor wouldn't budge the 18 wheeler. So you have to look at what kind of vehicle you drive and what kind of driving you will be doing before you decide if you need more torque of hp.