I would say like most everyone else has, straight is the better choice unless you are a lefty or plan on cutting seat belts, rope, plastics (softer LDPE type) a bunch. My swisstool has both a serrated and non-serrated blade and the only time I seem to use the serrated blade is when I cut into the plastic catch bins at work for new pipe placement or jury-rig "reconstruction". It slices through it so much better and is still relatively "easy" to resharpen as it is the older style scalloped edge and not the newer micro grooved edge that spyderco made so popular.

-Bill Liptak