I'm just curious to know which butter does everyone choose to use? I tried a few, read about butter when it comes to baking. I read one article European butter, one says Land o Lakes, and I use Great Value unsalted sweet cream butter. I've tried the Irish butter and liked it but it is really expensive. I tried the great value and like it. 

I used Land O Lakes exclusively until I tried it side by side with the Member's Mark brand at Sam's Club. I couldn't tell a difference between them and the Member's Mark is $11.98 for 4lbs, so I made the switch.

I am in Canada so we have different brands than you do in the U.S. and actually different brands depending on the provinces.  The one thing I do find that really makes a difference here and it is likely true in the U.S. too,  is the bargain brand butters quite often have a higher moisture content -  water content. Now that might not matter so much for some things but -  for example, I found when I did my Christmas cookie baking with one, the cookies spread out too much. I learned my lesson.  My preference is to get a good brand and stock up when it is on sale. A lot of people do swear by Land o Lakes. 

A lot of people do comment on European butters being creamier. I think due to the cost factor, I might save them for slathering on a scone where you really appreciate the taste.

I bake with both salted and unsalted/sweet butter as per the recipe.

I think people have their preferences. It will be interesting to see what people use.

I’ve used all the different butters — I prefer costco  or sam’s club brand — but the grocery store is closer so just depends on how much I need for the project— I buy unsalted butter 

I saw a segment on a Craftsy class on which butter to use.  The instructor went through the different types and the final conclusion was, when butter is the star of the recipe, as in croissants or buttercream, go for the top quality brands; for recipes like cakes or others where butter is not the keep ingredient, any brand works just fine.