I use the Planet Waves Black Ice(stupid name) 1.5mm
They last longer than the jazz III's and have a more refined tone(to me)
They are also slightly bigger and are much much cheaper.
I had a heavy Red Bear Tortise pick and it was great... But It wore down just like any other pick. Sounded bright and warm at the same time.
Are there any Jazz III styled picks that are made of delrin? I love the sound of the delrins (similar to the fender heavies), but have recently switched to the nylon jazz III's. I like the hard, brittle click of the delrins.
I use the Cool Picks Juratex Jazz picks. One very cool thing about them is as they wear, you can drag them through carper to "sharpen" the edge and make it new. I end up using a single pick for several weeks. Sure it gets smaller as time goes on, but not enough to worry about.