I haven't used or installed strings from every builder nor will I bash a string builder but.... These are the strings that I recommend to my customers and my thoughts on each:
Note - This list is based on the number of experiences that I have had with the string builder, MOST to LEAST.
1) 60X - Quality product and really quick turn around. In most cases, I can have them in my shop in a week. I'm a dealer for them and on the very few occasions there was an "issue", they did right by me and my customers. I've been shooting strings from 60X for 8 years and have a set on my hunting bow.
2) GAS - These strings come factory on the bows that I sell and have had excellent results with them. I'm not a dealer for them but, some of my customers are very loyal to Eric and his products. I've installed quite a few sets of these strings and they are also excellent quality. I have a set on my 3D bow.
3) Wicked Threads - I'm a dealer for this builder. Craig builds a helluva set of strings. Every set of strings I got from this builder have been spot on. I haven't had to add or remove a single twist and everything has been in spec right out of the package. These strings are quickly climbing up the leader board for number of sets that I've sold.
4) A3 Archery - I'm a dealer for this builder. Quick turnaround and excellent quality and competitively priced. I put a set on my spot bow and after thousands of shots over the last few months, the tune is just as spot on as the day I installed them.
5) Rogue - I'm not a dealer for this builder but the quality is excellent. I don't "see" why the R21 strings cost almost twice what other builders are charging but, they are great strings. 2 of my customers are on the Rogue shooting staff and they bring their stuff to me for installation.
6) Tall Tine/BC Strings - I'm not a dealer for either of these builders. I installed the customer supplied strings and they are happy with their decision to use them.
I'm sure there are other excellent builders out there.... I just don't have experience with them.