Subject says it all.
Guitar picks are relatively new to me since I only recently switched from nylon string to electric.
I have more or less settled on this fat little 1.5mm pick by Cool.
It’s a jazz pick, thick and stubby. I love the feel it gives me as it gently glides off the strings, producing those mellow jazz tones.
This little pick and a set of flatwound 12s are all I need.
What’s yours?
The fingernail on my index finger.
SX .96mm for electric and Jim Dunlop .60mm for acoustic.
I have always played in a very chunky, rhythmic style…relying much more on the physical impact of pick on strings than on electronics.
Therefore, I use nothing but Fender heavy-gauge triangular picks (I call them “Dorrito picks”).
I can’t imagine using the tiny, flimsy picks that many seem to favor, but that’s just down to my style of playing.
I’m a finger-style bassist myself but when I play guitar at church I use a 0.58 for my acoustic and electro-acoustic and a 0.85 for my electric.
Yeah, Dorito picks.
Jim Dunlop tortex 1 mm for everything. They’re blue 
Here’s one the size of a frisbee, I use the normal sized ones.
The right stiffness, tough, non-shiny and grippy. I used to use Fender heavys but they don’t wear as gracefully.
I’ve found that I can do pretty much everything I need to do, electric or acoustic, with Dunlop Tortex 1.14mm (the purple ones). On my acoustic they’re sometimes a little too “bright” so I use my index fingernail like Jack Batty mentioned above for strumming or all fingertips for more complex fingerpicking.
EDIT: Oh, and Tortex picks last freakin’ forever, at least the really thick ones do. When I used thin picks they were always getting nicks in the sides that were really obnoxious.
Fender Medium. I get a different colored pack every time.
Why do I feel like I’m revealing my condom brand or something? 
Regular old Dunlop nylon, either black (thicker) or dark grey (thinner). They do the job and never, ever break.
Oh yeah, the Fender picks were terrible for me. They were shiny and slippery, and no matter the thickness they would always notch up on the sides. No fun when one of those things grabs a string and either breaks the string or sends the pick flying unexpectedly.
I also prefer the Dunlop Tortex 1mm for guitar (electric and acoustic), for exactly those reasons. Tortex 1.5mm for mandolin (the dark green ones… actually, I’d use 'em for acoustic guitar too, but for whatever reason they end up shredding down into little nubs way quicker than the 1mm ones).
While I notice some difference in sound between different pick types, it’s nowhere near as important to me as the difference in feel. Or the ability to prevent dropping the damned things mid-strum.
Dunlop Tortex, purple for electric guitar and green for acoustic. No profound reason, I just like the feel of them.
0.88 Everly Star picks. Other picks tend to fly out of my hand during intense runs.
See, I used to use the Dunlop tortex picks, but they violated my basic Rule of Picks:
Thou Shalt Not Break.
Every tortex pick I’ve played has eventually split neatly right up the middle. Awkward in the middle of a song.
I don’t want to think about my picks. I merely want them to do their job and not break.
The Dunlop nylons are tough, they don’t break, and they have a nice, nubbly gripping surface.
I’ve evolved several times:
I started playing with Fender celluloid mediums, which I’d still like if they didn’t unexpectedly get toothy shaped wear on the edges, usually in the middle of a song. And you could light them on fire if you were bored, they burned like a candle.
Later I used Dunlop Jazz IIs and later Jazz III’s. Very small, very hard, close to indestructible. I still have one that I bought in the 80’s, and it doesn’t seem to be worn at all, 25-ish years later.
These days I use the Dunlop mediums (the purple ones), or Fender Derlin mediums. I like a little bendiness, but not too much.
I find that nylon picks don’t wear well – you get tattered edges. Though maybe Dunlop has improved the materials.
Interesting. I have not yet broken a Tortex, though I’ve broken plenty of other brand/style picks. And nearly everything else guitar-related at one point or another (not in the Pete Townshend sense, either).
I also like the Cool picks and the Dunlops, for their grippiness.
I’ve never broken a Dunlop Tortex either. I have some that I bought last month, and some that I bought in the early 80s. I generally can’t tell which is which.
These are the jazz picks, the ones with the rounded tips. I can’t use anything else. I’ve acclimated too much.
This, for a couple of decades. Anything else is either too hard or too soft. I bought some with rough material on them for grip which made me realise my picking technique isn’t “correct” as I seem to use most of the pick when I’m strumming, and the rough stuff made a horrible noise and looked like it would damage the strings. So I reverted to the Dunlops.
I play 99% acoustic and fairly aggressively, so I like the Fender triangular flatpicks, medium gauge.
I also like the green Tortexes.
