I have never given much thought to pick choice. I started using yellow Tortex picks in 1996, which I continued to use to this day. I have recently been playing quite a bit and thought that doing a deep dive on picks might be a fun and cheap experiment (and it has been). I bought a pretty variety of shapes (standard, sharp, jazz I and III, jazz xl, traingles, small triangles, etc), thicknesses, and materials (nylon, celluloid, delrin, and utlex). I played them all on different guitars, acoustic and electric, and graded them on different techniques. It was pretty interesting. Alot of my preferences were purely aesthetic. For example, ultex felt "brittle," and I did not like the way that sharp jazz tips felt going across the strings. SHAPE- Seeing all of the folks who used jazz IIIs, and having never tried one myself, was the impetus for my experiment. But as noted, I did not like the way that any of the jazz tips felt across the strings. At the end of the day, the standard shape won out for me. I also noticed that I had, unknowingly, developed techniques over the years in which I moved the pick around in my grip and changed my grip. MATERIAL- I preferred delrin/tortex above the other materials. It felt the best to me. Nylon felt too slick on the strings and was not stiff enough, even at 1mm. Celluloid felt pretty good, but not as good as the delrin- it was just too slick. Outside of how they feel, delrin picks are good because they are cheap, relatively durable, and can be purchased at any music store. THICKNESS- This was the most interesting aspect to me. The orange tortex was the best strumming pick- it felt great going across the strings. The most noticeable difference occurs when you go from the yellow to the green tortex. The yellow is a much better strummer than the green, but during fast picking phrases, the yellow "lags" a bit, whereas the green is a great picker. This "breaking point" might account for why the yellow and green are the most popular among pros and amateurs, they are good all-rounders with the yellow favoring strumming and the green favoring picking. Moving up, I can't feel a whole lot of difference between the green and blue, they both feel really good. The purple just felt too thick hitting against the strings and was uncomfortable to strum. When it comes to "the pick" that I keep in my wallet, I want something that is definitely a good picker because I can always make do on strumming, but not vice versa. Therefore, I think my sweet spot for an all-rounder is somewhere around a green or blue tortex- I am going to put both of these through long haul tests to see if one comes out on top. I will also keep an orange tortex or two around as a strumming pick. I would be interested to hear anybody's preferences and how they came to it. Also, I wanted to post a poll for Tortex players: which color do you play?