i recently read a review of seam rippers in a quilt magazine.
They recommended the Bernina which I have and like. However, the recommendation was to get one that has a thin point. Several on the market but the thin top is best.
Clover makes a nice gadger (can't remember the name now) but looks like a very thin crochet hook. It is great for ripping out stitches. I have one sitting by each machine and in every sewing box.