which yeast should be prefered? instant or dry active?

I use active dry, as others have stated.

I have always disliked instant yeast. I find it doesn't rise the dough as evenly. And the regular dry yeast rises just about as fast.
I have used SAF yeast exclusively for years, and find it to be superior to the brands sold in supermarkets. I don't proof it separately, just mix right in and along with the other dry ingredients. A breeze!

From what I understand Active is preferable when there is a longer rise period (for example, an overnight rise in the refrigerator) and Instant is best for shorter faster rising periods. So it depends on the type of bread you are making.

I'm not sure what instant yeast is- different yeast or different treatment? I usually buy active dry yeast at Costco in 2 pound bags (about $5, which will get you maybe 4 oz. at the grocery store)- that's a lot for me to use up, so I don't muck aboot much with other types.

There are basically 3 types available commercially - fresh (in cubes, refrigerated); active dry & instant (on pantry or dry shelves, in envelopes or jars). All work in most bread recipes, but the instant is specified sometimes for recent recipes that work in shorter time. You can also use sourdough starter (if you have one going on your counter).

Oops. I meant that I use instant more often!

I tend to use active more often. You can use it in a recipe that calls for active dry, but not the other way around.