I suppose that my favorites also are the cutter and mats. I have a very large rotating one that is wonderful. But I mostly use the 35 by 40 regular one.
I love my snip sissors for sewing. No holes to get my fingers stuck in.
My quarter inch foot with the fabric guide is a must now too.
Clover stelleto, tiny iron and smallish iron mat so I don't have to get up to press across the room.
And here is my tip if you can't find the sewing machine needles that you barely use and have to change out. I bought a tomato pin cushion and wrote on the little quadrants the numbers of the sizes I use. Then I just push the slightly used needle into the pie shape with the right number. Easy as pie to find it now!